400% Deposit Bonus Casinos UK: The Real Maths Behind the Offer

A 400% deposit bonus sounds like the single best deal on the UK market. Put in £20, get £80 to play with. Put in £50, get £200. The arithmetic is simple and that is exactly why operators use it: the headline percentage does the selling, and the wagering terms do the earning. This page breaks down what a 400% bonus actually costs you in expected value, which UK-licensed brands still run offers in this range, and where the maths quietly falls apart.

Most UK-facing casinos cannot legally advertise a 400% matched deposit as a straightforward cash perk. Under Gambling Commission rules, bonus funds are not withdrawable until wagering conditions are met, and since October 2022 the minimum wagering requirement sits at 10x the bonus amount. That single number changes everything about how a 400% offer should be judged.

What a 400% Deposit Bonus Actually Means in 2026

A 400% deposit bonus is a matched deposit promotion where the casino credits bonus funds equal to four times your qualifying deposit. Deposit £25 and you receive £100 in bonus credit, giving a total playable balance of £125. The bonus is not cash. It sits in a separate wallet, cannot be withdrawn directly, and converts to real money only after you meet the wagering requirement attached to it.

The UK market has moved a long way from the 2015-era model where 400% and even 500% offers were plastered across television advertising. The Gambling Commission's 2020 ban on credit card deposits, the 2021 ban on autoplay, and the 2022 tightening of bonus terms pushed almost every major British operator toward smaller, cleaner welcome packages. Bet365, William Hill, Sky Bet, Ladbrokes and Paddy Power now run welcome offers in the £10 to £50 range with 20x to 40x wagering, not 400% matches.

Where 400% offers survive, they tend to sit with offshore operators, crypto casinos, or brands using a "bonus crab" structure where the percentage applies to a very small qualifying deposit. A 400% match on a £5 minimum deposit gives you £20 of bonus funds. That is a real offer, but it is not the £500 windfall the banner implies.

Is a 400% bonus the same as free money?

No. Bonus funds are promotional credit, not withdrawable cash. You must wager the bonus a set number of times before any of it converts. On a 400% offer with 40x wagering on the bonus, a £100 bonus requires £4,000 of total stakes. Until that threshold is cleared, the balance is a playing credit with a conversion condition attached.

Why do operators advertise 400% if UK rules are so tight?

Because the percentage is a marketing device, not a value guarantee. A 400% match on a £5 deposit with 60x wagering is worth less in expected value than a 100% match on £50 with 20x wagering. The percentage is the sizzle; the wagering requirement, game weighting and maximum conversion cap are the substance.

The Maths: Expected Value of a 400% Bonus

Expected value (EV) is the only honest way to compare deposit bonuses. The formula is straightforward: EV = Bonus Amount − (Total Wagering × House Edge). If the result is positive, the bonus is worth taking on paper. If it is negative, you are paying for the privilege of playing with the operator's money.

Take a typical 400% offer: £25 deposit, £100 bonus, 40x wagering on the bonus, slots contribute 100%, average slot RTP 96% (house edge 4%). Total wagering is £4,000. Expected loss from wagering is £4,000 × 0.04 = £160. The bonus is worth £100. Net EV = £100 − £160 = −£60. You are expected to lose £60 of your own money chasing a bonus worth £100.

Now compare that to a 100% match: £50 deposit, £50 bonus, 20x wagering on the bonus, same 96% RTP slots. Total wagering is £1,000. Expected loss is £1,000 × 0.04 = £40. Net EV = £50 − £40 = +£10. The smaller, less glamorous offer is the better deal by £70.

The pattern is consistent. The higher the match percentage, the worse the EV almost every time, because operators price the generosity into the wagering. A 400% offer with 40x wagering is a worse deal than a 50% offer with 10x wagering by a factor of roughly six.

How does game weighting change the calculation?

Slots usually contribute 100% to wagering. Table games like blackjack, roulette and baccarat typically contribute 10% or even 0%. A £10 blackjack bet on a 10% weighting counts as £1 toward the requirement. If your 400% bonus requires £4,000 of wagering, playing blackjack means £40,000 of actual stakes. That is not a realistic target.

What is the maximum conversion cap and why does it matter?

Many 400% offers cap the maximum you can convert from bonus to cash. A common cap is 4x the bonus amount, so a £100 bonus can convert to at most £400. If you run hot and turn that £100 into £2,000, you still only withdraw £400. The cap is the single most under-read clause in the terms.

UK-Licensed vs Offshore: Where 400% Offers Live

The UK Gambling Commission does not ban 400% bonuses outright. It bans the marketing practices that made them misleading, and it enforces strict rules on how bonus terms are displayed. In practice, most UK-licensed operators have abandoned the 400% headline because the compliance cost and the negative press outweighed the acquisition benefit.

That leaves two categories of 400% offer. The first is offshore: Curacao, Anjouan or Kahnawake-licensed casinos that accept UK players without a UK licence. These are legal for you to play at, but you lose UK Gambling Commission protection, the UK dispute resolution scheme, and access to GamStop. The second is UK-licensed brands running 400% offers on specific products, usually bingo or a niche slot mechanic rather than a general deposit match.

Gala Bingo, Foxy Bingo, JackpotJoy and Sun Bingo have historically run percentage-based bonuses tied to bingo ticket purchases rather than slots. These are usually structured as 300% to 500% on a first ticket bundle, with wagering applied to bingo play rather than casino games. That is a materially different product from a slots deposit match.

Which UK-licensed brands still run large percentage offers?

Very few run a true 400% deposit match on slots. Gala Bingo, Foxy Bingo and JackpotJoy run large-percentage bingo bonuses. MrQ, PlayOJO and Casumo have built their positioning on low-wagering or no-wagering offers instead of high-percentage matches, which is the opposite strategy. Betfred, Coral and BoyleSports stick to 100% matches with 20x to 40x wagering.

Are offshore 400% offers worth the risk?

Sometimes, on pure EV terms, an offshore 400% with 25x wagering on a 97% RTP slot can beat a UK 100% with 40x wagering. But you are trading regulatory protection for a few pounds of theoretical EV. The UK Gambling Commission's dispute process, the requirement that operators segregate player funds, and GamStop integration all disappear offshore. For most players, that trade is not worth it.

Top Operators Running Bonus Offers in the 400% Range

The UK market's biggest names have moved away from 400% matches, but several still run percentage-based offers that reach or approach that level on specific products. Below is a breakdown of the operators most commonly associated with large-percentage promotions, with the actual structure of what they offer.

Read that table carefully. The only operators running offers at or near 400% are the bingo-focused brands: Gala Bingo, Foxy Bingo, Sun Bingo and JackpotJoy. Their wagering is also dramatically lower, typically 2x to 4x on bingo ticket value rather than 40x on slots. That combination makes the bingo 400% offers meaningfully better EV than a hypothetical slots 400%.

On the slots side, the market has standardised around 100% matches with 20x to 40x wagering. Bet365, William Hill, Sky Vegas, Ladbrokes, Paddy Power, Coral, Betfred, 888, Casumo, LeoVegas, Unibet, Betfair, Grosvenor and Genting all sit in this bracket. MrQ and PlayOJO have gone the other direction entirely, offering no-wagering spins where winnings are withdrawable as cash.

Why do bingo sites run 400% and slots sites do not?

Bingo has a much lower house edge than slots, typically 10% to 20% on ticket sales versus 2% to 8% on slots. A 400% bingo bonus with 2x wagering has positive EV for the player in many cases, which is why bingo operators can afford to run it. Slots operators cannot match that structure without losing money on every acquisition.

Which operator has the best real-world value?

On pure EV, MrQ and PlayOJO win because their no-wagering spins convert to cash with zero expected loss. On percentage headline, Gala Bingo and Foxy Bingo win with 400% offers. On brand trust and regulatory protection, Bet365, William Hill and Sky Bet lead. There is no single winner; it depends on what you value.

Wagering Requirements: The Number That Decides Everything

Wagering requirement is expressed as a multiplier. "40x" means you must stake 40 times the bonus amount before any of it becomes withdrawable. A £100 bonus at 40x requires £4,000 of qualifying stakes. At 10x, the same bonus requires £1,000. The difference in expected loss at 96% RTP is £120.

UK Gambling Commission rules set a floor: the minimum wagering requirement is 10x the bonus amount. Operators can go lower but not higher than... actually, they can go higher. The 10x figure is the minimum below which an offer cannot be described as a "bonus" in certain marketing contexts. Most UK operators sit at 20x to 40x.

There is also the question of what the wagering applies to. "40x on bonus" means 40 times the bonus. "40x on deposit + bonus" means 40 times the combined amount. On a £25 deposit + £100 bonus, that is 40 × £125 = £5,000 of stakes, not £4,000. Always check which base the multiplier applies to.

What counts toward wagering and what does not?

Slots almost always count 100%. Live dealer games usually count 10% or 0%. Table games like blackjack, roulette and baccarat typically count 10% or 0%. Some operators exclude specific high-RTP slots entirely. Pragmatic Play, NetEnt, Microgaming, Evolution and Hacksaw Gaming titles are usually included at 100% on slots, but individual games can be excluded.

Does the wagering clock reset if I deposit again?

Usually not, but some operators apply a 30-day window from the date the bonus is credited. If you do not clear the wagering within that window, the bonus and any winnings from it are removed. Check the expiry term before you deposit. A 30-day window on £4,000 of wagering means £133 of stakes per day.

RTP Differences: Why the Slot You Choose Matters More Than the Bonus

Slot RTP is the single biggest lever on bonus EV, and it is the one most players ignore. A 96% RTP slot has a 4% house edge. A 94% RTP slot has a 6% house edge. On £4,000 of wagering, that 2% difference is £80 of expected loss. The bonus is worth £100. Choosing the wrong slot can wipe out most of the bonus's value.

UK-licensed operators are required to publish RTP on each game, and the UK average sits around 95% to 96% on slots. Offshore operators often run the same games at lower RTP settings. A Pragmatic Play slot configured at 96.5% on a UK site might run at 94% on an offshore site. Same game, same graphics, different maths.

This is the most under-discussed point in the entire 400% bonus conversation. Players obsess over the percentage match and ignore the fact that a 2.5% RTP difference on £4,000 of wagering costs £100. The bonus structure is a red herring; the RTP is the real cost.

How do I check a slot's RTP before playing?

Open the game's information panel or help screen. UK-licensed operators must display the RTP. Look for the "Return to Player" figure, usually listed as a percentage. If you cannot find it, the game is probably not UK-licensed or the operator is not compliant. Walk away.

Do all games from the same provider have the same RTP?

No. NetEnt's Starburst runs at 96.09% at most UK operators. Pragmatic Play's Sweet Bonanza runs at 96.51%. But individual titles vary, and some providers offer multiple RTP configurations of the same game. Always check the specific title, not the provider's average.

How to Calculate Whether a 400% Bonus Is Worth Taking

The calculation takes about two minutes and will save you more money than any bonus hunting strategy. You need four numbers: the bonus amount, the wagering requirement, the base the wagering applies to, and the RTP of the slot you plan to play.

1. Multiply the wagering multiplier by the base amount to get total stakes required.
2. Subtract the RTP from 100% to get the house edge (e.g., 96% RTP = 4% edge).
3. Multiply total stakes by the house edge to get expected loss.
4. Subtract expected loss from the bonus amount to get net EV.

If net EV is positive, the bonus is worth taking on pure maths. If negative, you are paying for the privilege of playing with promotional credit. Most 400% offers come out negative. Most 100% offers with 20x wagering come out slightly positive.

There is one more factor: variance. EV is a long-run average. In a single bonus cycle, you might clear the wagering and withdraw £300, or you might bust on the first £50 of stakes. The maths tells you the average outcome, not your outcome. Treat a positive-EV bonus as a small edge, not a guaranteed profit.

What is a realistic expected outcome on a 400% bonus?

On a £25 deposit with £100 bonus at 40x wagering and 96% RTP, the expected loss is £160 against a £100 bonus. That is a net EV of −£60. In practice, roughly 60% to 70% of players bust before clearing the wagering. The bonus is structured so the operator profits on average.

Can I profit from 400% bonuses long-term?

Only if you find offers with positive EV and clear them systematically. That means low wagering (10x or less), high RTP slots (97%+), and no maximum conversion cap. These offers exist but are rare, and operators restrict accounts that bonus-hunt aggressively. For most players, the honest answer is no.

Bonus Terms That Quietly Kill the Value

Every 400% bonus comes with a terms page that most players never read. The headline percentage is on the banner; the clauses that decide whether you actually get paid are in the small print. Here are the ones that matter most.

Maximum conversion cap. Some offers limit how much you can convert from bonus to cash. A 4x cap on a £100 bonus means you can withdraw at most £400, no matter how much you win. If you hit a £5,000 jackpot on bonus funds, you keep £400.

Maximum bet during wagering. Most bonuses cap your stake at £5 per spin or £5 per hand while wagering. Exceed it and the bonus is voided. Some operators set the cap at £2.50. This is the most common reason players lose their bonus without realising.

Game exclusions. Specific high-RTP slots are often excluded from wagering entirely, or contribute at reduced rates. A 97% RTP slot is exactly the game you want to play to maximise EV, and it is exactly the game operators exclude.

Expiry windows. 7 days, 14 days, 30 days. A 7-day window on £4,000 of wagering means £571 of stakes per day. That is not realistic for a casual player, and the bonus expires before you clear it.

What is the most common reason players lose a bonus?

Exceeding the maximum bet during wagering. A £5 cap sounds generous until you realise that a £10 spin voids the entire bonus and any winnings from it. Read the max bet clause before you place a single spin. It is usually listed in the bonus terms summary.

Are winnings from bonus funds always withdrawable?

No. Winnings from bonus funds are themselves bonus funds until the wagering is cleared. Only after you meet the full requirement does the balance convert to cash. If you withdraw early, the bonus and any winnings from it are removed. Plan to clear the wagering or do not take the bonus.

Safer Alternatives to 400% Bonuses

If the maths on a 400% offer does not work, the question becomes what does. The UK market has moved toward three structures that offer better real-world value than a high-percentage match.

No-wagering spins. MrQ and PlayOJO built their entire propositions on this model. You get a set number of free spins with no wagering requirement. Any winnings are paid as cash. A 10-spin no-wagering offer on a 96% RTP slot has positive EV because there is no expected loss from clearing a requirement.

Low-wagering deposit matches. A 100% match at 10x wagering on a 97% RTP slot has an EV of roughly +£30 on a £50 deposit. That is a better deal than almost any 400% offer on the market.

Cashback and loyalty schemes. Some operators pay back a percentage of net losses as cash or bonus. A 5% cashback on £1,000 of losses is £50 back. No wagering, no caps, no expiry. It is not a headline-grabbing offer, but it is real value.

Are no-wagering offers always better than 400% bonuses?

Not always, but usually. A no-wagering offer has zero expected loss from clearing a requirement, so its EV is simply the value of the spins or bonus. A 400% offer with 40x wagering has an expected loss that often exceeds the bonus amount. The maths favours no-wagering in the vast majority of cases.

Which UK operators offer no-wagering or low-wagering bonuses?

MrQ and PlayOJO are the two most consistent no-wagering operators in the UK market. Casumo, LeoVegas and Unibet run low-wagering offers (20x to 25x) more often than the market average. Bet365, William Hill and Sky Bet stick to standard 20x to 40x structures but compensate with brand trust and regulatory protection.

Regulatory Context: What UK Law Says About Bonus Offers

The Gambling Commission's rules on bonuses changed significantly between 2020 and 2022. The key changes were the ban on credit card deposits (April 2020), the ban on autoplay on slots (October 2021), the reduction of online slot stake limits to between £2 and £15 per spin depending on age and risk profile (2025), and the tightening of bonus terms disclosure requirements.

Operators must now display bonus terms in a standardised format, with the significant conditions shown alongside the offer rather than buried in a separate terms page. The 10x minimum wagering requirement was introduced as part of this framework. The Gambling Commission also requires operators to allow players to withdraw bonus funds before meeting wagering, provided they forfeit the bonus.

These rules apply only to UK-licensed operators. Offshore casinos accepting UK players are not bound by them, which is why the 400% offers that survive tend to sit offshore. If you play at an offshore casino, you are playing under a different regulatory regime with different protections.

Can I withdraw my deposit before clearing the bonus?

Yes, at UK-licensed operators. You can withdraw your original deposit at any time before meeting the wagering requirement, but doing so forfeits the bonus and any winnings from it. Some operators process this automatically; others require you to contact support. Check the terms.

What happens if an operator goes bust while I have bonus funds?

At UK-licensed operators, player funds are segregated from operating funds, so your deposit is protected even if the operator fails. Bonus funds are not always protected in the same way. At offshore operators, there is no segregation requirement and no UK dispute resolution scheme. This is the practical cost of playing offshore.

How to Claim a 400% Bonus Safely

If you have run the maths and decided a 400% offer is worth taking, the process is straightforward. Register at the operator, complete age and identity verification, make a qualifying deposit using a method that counts (debit card, bank transfer, or e-wallet), and opt in to the bonus if required. Some operators apply the bonus automatically; others require a promo code.

Before you deposit, check three things: the wagering requirement and what it applies to, the maximum bet during wagering, and the expiry window. If any of those three is unclear or unfavourable, do not deposit. The bonus is not worth the hassle if you cannot realistically clear it.

Once the bonus is active, stick to high-RTP slots that contribute 100% to wagering. Avoid live dealer games and table games unless you have checked their contribution rate. Track your wagering progress in the bonus section of your account. If you are not going to clear it within the window, stop playing and forfeit the bonus rather than chasing it.

What deposit methods qualify for a 400% bonus?

Debit card, bank transfer and e-wallets like PayPal, Skrill and Neteller usually qualify. Credit cards do not, since the April 2020 ban. Some operators exclude e-wallets from bonus eligibility because they are easy to use for bonus abuse. Check the terms before depositing.

Can I claim a 400% bonus if I already have an account?

Usually not. Welcome bonuses are for new customers only. Existing customers may have access to reload bonuses, but these are typically smaller (50% to 100%) and have higher wagering. Some operators run "second deposit" bonuses at 200% to 300% for existing players, but these are less common than they were in 2018.

Responsible Gambling: The Non-Negotiable Rules

Bonus maths is interesting, but it does not change the fundamentals. Gambling is a negative-EV activity for the vast majority of players. Bonuses shift the EV slightly in your favour in rare cases, but they do not make gambling profitable. If you are playing to make money, you are playing the wrong game.

The legal age for gambling in the UK is 18. If you or someone you know is struggling with gambling, the National Gambling Helpline is available 24/7 on 0808 8020 133. GamStop is the UK's self-exclusion register, and you can sign up at gamstop.co.uk to block yourself from all UK-licensed gambling sites for a minimum of 6 months, extendable to 5 years. GamCare offers free counselling and support.

Set deposit limits before you start. Most UK-licensed operators require you to set a limit within 24 hours of opening an account, and the limit cannot be increased for 24 hours after you request a change. Use this. A £50 monthly deposit limit is a real constraint; a £500 one is not. Time limits and reality checks are also available at most operators.

A 400% bonus is not a reason to gamble more than you would otherwise. It is a promotional credit with conditions attached. If the conditions do not suit you, do not take the bonus. The offer will still be there tomorrow, and so will the maths.

Where can I get help with a gambling problem?

The National Gambling Helpline is 0808 8020 133, available 24 hours a day, 7 days a week. GamCare provides free counselling. GamStop is the self-exclusion register at gamstop.co.uk. If you need to block yourself from gambling, GamStop is the fastest route and covers all UK-licensed operators.

What is the minimum age to gamble in the UK?

18 for most forms of gambling, including online casinos, slots and sports betting. Some lottery products are available from 16. National Lottery scratchcards and draw-based games are 18+. The legal age is enforced by the Gambling Commission and operators must verify age before allowing deposits.

FAQ: 400% Deposit Bonus Questions Answered

Is a 400% deposit bonus worth taking?

Usually not, on pure EV. A 400% match with 40x wagering on a 96% RTP slot has an expected loss of £160 on a £100 bonus, giving a net EV of −£60. A 100% match with 20x wagering has a net EV of around +£10. The smaller offer is the better deal.

Which UK casinos offer 400% deposit bonuses?

Very few UK-licensed slots operators run a true 400% match. Gala Bingo, Foxy Bingo, Sun Bingo and JackpotJoy run 400% offers on bingo ticket bundles with 2x to 4x wagering. On slots, Bet365, William Hill, Sky Vegas and Ladbrokes stick to 100% matches with 20x to 40x wagering.

What wagering requirement comes with a 400% bonus?

Typically 30x to 40x on the bonus amount for slots offers, or 2x to 4x on bingo ticket value for bingo offers. The UK Gambling Commission's minimum is 10x. Always check whether the multiplier applies to the bonus alone or to deposit plus bonus combined.

Can I withdraw a 400% bonus immediately?

No. Bonus funds are not withdrawable until the wagering requirement is met. You can withdraw your original deposit at any time, but doing so forfeits the bonus and any winnings from it. Only after clearing the full wagering does the bonus convert to cash.

Are 400% bonuses from offshore casinos safe?

They are legal for UK players to use, but you lose UK Gambling Commission protection, the UK dispute resolution scheme, and GamStop coverage. Offshore operators are licensed in jurisdictions like Curacao or Anjouan with lighter regulatory requirements. The EV may be better; the protection is weaker.

What is the maximum I can win from a 400% bonus?

Many offers cap conversion at 4x the bonus amount. A £100 bonus with a 4x cap means a maximum withdrawal of £400, regardless of how much you win. Check the maximum conversion clause before depositing. Some offers have no cap; most do.

Do no-wagering offers beat 400% bonuses?

On expected value, almost always. A no-wagering offer has zero expected loss from clearing a requirement, so its EV is the full value of the spins or bonus. A 400% offer with 40x wagering has an expected loss that often exceeds the bonus amount. MrQ and PlayOJO are the leading UK no-wagering operators.

How do I calculate the real value of a deposit bonus?

Multiply the wagering multiplier by the base amount to get total stakes. Multiply total stakes by the house edge (100% minus RTP). Subtract that from the bonus amount. If the result is positive, the bonus has positive EV. If negative, you are paying to play with promotional credit.

What is the minimum age for claiming a casino bonus in the UK?

18. All UK-licensed operators must verify age before allowing deposits or bonus claims. the Gambling Commission's licence conditions, age verification must be completed before a player can deposit, and operators face fines running into millions if they allow underage play. There is no workaround, no grace period and no exception for a bonus claim.

Do 400% bonuses expire if I do not use them?

Yes. Most carry a 7-day, 14-day or 30-day window from the moment the bonus is credited. Miss it and the bonus plus any winnings built from it disappear. A 7-day expiry on £4,000 of wagering works out at £571 of stakes per day, which is out of reach for most casual players.

Can I hold bonus funds at more than one casino at once?

Technically yes, but it is a poor idea. Running two wagering requirements in parallel splits your attention and your bankroll, and neither clears faster. Operators also share data through industry schemes, and players who claim multiple welcome bonuses at once are often flagged and restricted.

What happens if I breach the maximum bet rule?

The bonus is voided, along with any winnings generated from it. Your original deposit usually stays intact, but everything built on top of the promotional credit is removed. A £5 cap sounds generous until you realise a single £10 spin can wipe out hundreds in accumulated winnings.

Are 400% bonuses better on mobile than desktop?

The maths is identical. The same wagering requirement, the same RTP and the same maximum bet cap apply regardless of device. What changes is your ability to check terms quickly and track wagering progress, which is easier on a larger screen. Do not let app convenience push you into a faster deposit.

How long does it take to clear a 400% bonus in practice?

On £4,000 of wagering at an average of £2 per spin, you need 2,000 spins. At 600 spins per hour, that is a little over three hours of continuous play. Add the variance of actually surviving that run on a 96% RTP slot, and the realistic figure is closer to five or six hours.

Does the bonus percentage affect the RTP of the games?

No. RTP is set by the game provider and the operator's configuration, not by the bonus you are playing with. A 400% bonus does not make a slot pay more or less. What it does is extend your playtime, which gives the house edge more spins to work through. That is the entire mechanism.

The Bottom Line on 400% Deposit Bonuses

The percentage on the banner is a marketing number. The number that decides whether you come out ahead is the wagering requirement, and behind that sits the RTP of the slot you choose to play. Get those two wrong and a 400% offer costs you more than a 50% one.

Run the arithmetic before you deposit. Bonus amount minus expected loss from wagering. If the answer is negative, the offer is not a gift, it is a fee. On most 400% matches with 30x to 40x wagering, the answer is negative by a wide margin, and the honest move is to take a smaller match with cleaner terms instead.

Where 400% offers do work, they tend to be bingo bundles with 2x to 4x wagering rather than slots matches. Gala Bingo, Foxy Bingo and Sun Bingo sit in that bracket, and their structures are genuinely better value than a hypothetical 400% slots offer. The maths is not close.

Play within limits you set before you open the account, check the RTP on every game you touch, and treat every bonus as a promotional credit with strings attached rather than free money. Do that and a 400% headline stops being tempting and starts being readable. That is the whole point.