The true cost of an online casino bonus

How much does 'free' money cost?

Whatever type of casino bonus is on offer - 1 hour free play, 100% match, 200% match, sign-up bonus - it eventually comes to a point where you have to release a sum of money from the bonus account into your real money account. And this is where it starts to cost.

In order to 'unlock' the bonus amount, you'll have to wager ie risk some of your own - often many times more than the bonus is worth. It's all stated quite clearly in the bonus terms and conditions, but it's not always as easy to understand as you might like.

How to calculate the cost of a bonus

There are three important elements in understanding how much a bonus will cost you:

1. the wagering requirement
2. the game contributing percentage
3. the game's house edge

1. Wagering requirement

A bonus's wagering requirement is the number of times the deposit plus bonus amount must be wagered before the bonus is released. It varies by bonus and by casino, but on average it's between 20 and 40 times - eg Rushmore's sign-up bonus is 20 times, and Bodog's is 40.

Our casino bonuses page has a list of bonuses ranked by wagering requirement - Click here to see it.

2. Game contributing percentage

The contributing percentage is the amount that each individual game counts towards the overall wagering requirement. Think of it like a multiplier: if the wagering on a game only counts as 50%, in effect you have to wager twice as much.

For slots players, the contributing percentage is normally 100%, so the wagering requirement stays at the basic level.

The difficulty starts with games like Baccarat, Blackjack and Roulette. For those games, each casino has its own opinion, but generally the contributing percentage will be 50% or less.

Take Blackjack, for example, where at Microgaming casinos the percentage is just 8%. What this effectively means is that the wagering requirement is actually 375x (100 / 8 x 30).

The contributing percentage varies by game, casino and bonus, so can get quite complex.

Our casino bonuses page lists bonuses by game (eg best Blackjack bonus) so you can see exactly what the wagering is for a particular game on any of our casino bonuses - Click here to see the lists.

3. House edge

In simple terms, the house edge is the percentage of total bets taken that the casino expects to keep in the long term. So in a game with a house edge of 2%, the casino will expect to make an overall profit of 2%.

All games have a house edge, ranging from less than 1% in some Blackjack variations to over 50% in some of the worst Keno bets.

Each game's house edge will affect the amount of game time you'll need before you can expect to show a profit.

The exceptions to this are the four games at Betfair's Zero Lounge which, as the name suggests, have NO house edge, though no bonus is available for play on the Zero Lounge games - for obvious reasons!

The casino bonus trap

The casino bonus trap is this:

the wagering requirement, contributing percentages and house edge combine to ensure that your betting is at a level where the expected loss is greater than the bonus amount.

Gambling without a bonus, your expected loss (ie the amount you should be prepared to lose) can be calculated as:

Expected loss = Amount wagered x House edge

(eg if you bet 2000 on a game with a 1.5% house edge, you should expect to lose 30)

Gambling to release a bonus, the amount you have to wager is dictated by the wagering requirement and the game percentage, so:

Amount wagered = (Deposit + Bonus) x Wagering requirement x (100 / Game %)

In other words,

Expected loss = ((Deposit + Bonus) x Wagering requirement x (100 / Game %)) x House edge

Example Blackjack bonus

Say you've taken up a 100% match bonus of 50 to play Blackjack (House edge is 0.5% or 0.005)

Your expected loss is therefore:

((50+50) x 30 x (100 / 10)) x 0.005

which gives you a figure of 150.

In other words, the amount you have to gamble in order to release the 50 bonus should, on average, incur a loss of 150!

This is the true cost of an online casino bonus and a clear indication of why you should think carefully before taking up an online casino's bonus offer.

Do you recommend any bonuses?

If you're a Slots player, then any of our casino bonuses will work for you - they all have 100% game contribution. But the best Slots bonus by far is Rushmore's Slots bonus which gives you a 400% match up to $2400 with just 20x wagering.

Bodog's 100% bonus up to £50 has a wagering requirement of 40x but Blackjack counts 100%. The expected loss on a £50 deposit would therefore be -

(50 + 50) x 40 x (100 / 100) x 0.005

which equals 45. On a deposit of £50, that's still a profit of £5.

The 1 hour free play bonuses are useful in that they give you a flavour of the casinos without having to risk anyof your own money. They're a good way to try out systems and strategies for selected games. But once your hour is up, you're back with a basic bonus with wagering requirements and contributing percentages, so all the above applies.

We recommend using them as a taster of the casinos that offer them, but don't see them as a 'free' money bonus.

Are casino bonuses worth taking up?

Bonus promotions are a way to attract new players to the casino. They're not really designed for serious gamblers. It's important to remember that you don't have to take out a bonus in order to play at any online casino. But if you do, make sure you know exactly what's required of you - before you start to play!