Frequently asked questions
Answers to the most common questions about BonusWijs.nl and our calculations.
What is BonusWijs.nl?
BonusWijs.nl is an independent information platform that calculates the expected value (EV) of welcome bonuses at licensed Dutch online casinos. We use mathematics to show what a bonus is really worth after wagering requirements.
What is expected value (EV)?
Expected value is the amount a bonus earns or costs you on average, expressed in euros. A positive EV (+€51) means the bonus offers a mathematical advantage. A negative EV (−€20) means you lose money on average. The calculation takes into account the bonus value, wagering requirements, RTP and game weighting.
How do you calculate EV?
The formula is: EV = effective bonus − expected loss. The expected loss is the total wagering requirement × the house edge (1 − RTP). We use the RTP published by the casino, not the theoretical maximum RTP from the provider. See our methodology page for the full explanation.
Are your calculations exact?
Our calculations are mathematical estimates based on the official bonus terms. They assume a constant bet per spin and do not account for bonus features that change variance. The actual result per session can vary significantly due to luck (variance), but over many sessions it converges toward the EV.
Can I make money with casino bonuses?
Most casino bonuses have a negative expected value — you lose money on average. A small number of bonuses (especially free spins without wagering requirements) have a positive EV. But even with a positive EV, that does not guarantee a profit per session. The casino always has a mathematical edge on the games themselves.
Why does the site say 24+?
Dutch law (Kansspelautoriteit) requires that bonuses and promotions may only be shown to players aged 24 and over. Players between 18 and 23 may gamble but cannot participate in bonus offers.
How often is the data updated?
All bonus data is regularly checked manually against the official terms on the casino website. Each casino page shows the date of the last check. Our system automatically alerts when data is older than 30 days.
Do you offer gambling services?
No. BonusWijs.nl is purely an information platform. We do not offer gambling services, accept deposits or manage player accounts.
What is the difference between wagering on 'bonus' and 'bonus + deposit'?
With wagering on 'bonus', only the bonus amount is multiplied (e.g. 30× €100 bonus = €3,000). With 'bonus + deposit', the bonus and deposit are added together (e.g. 30× (€100 bonus + €100 deposit) = €6,000). The second type is significantly more expensive — you have to wager twice as much.
Why do some casinos have a warning on their page?
Casinos with an expected value worse than −25% of the deposit automatically receive a red warning. This means the wagering requirements are so high that you lose a large portion of your deposit on average. We always recommend reading the terms carefully before accepting a bonus.
Can't find your question? Contact us at info@bonuswijs.nl.
Want to know more about our calculations? Read the methodology.