Bonuses have become a fixture of online gaming. They shape how players engage, how long they stay, and what they choose to play. Yet not all games respond to them in the same way.

Slots have emerged as the most natural fit. Their structure allows bonuses to play out smoothly, their mechanics give clear feedback, and their variety keeps players interested without complication. Compared with table games or live casino formats, they offer a level playing field with simple rules and transparent rewards.

Ville Saari, Lead Content Manager at Bojoko, has spent more than ten years analysing how slot bonuses in the UK shape player behaviour and influence modern game design.

In this conversation, he explains why slots remain the most balanced environment for casino bonuses, how regulation is ensuring fairer offers, and why clarity matters more than size.

Why do slots work so well with bonuses?

Slots are pretty much built for bonuses. You have your deposit bonus, which can basically be called a slots bonus, and then you have free or bonus spins that are generally played in slots.

Most modern slots sit between 94 and 97 per cent RTP, which means a large part of what you stake cycles back into play. That gives you time to enjoy the game and actually experience the bonus rather than burning through it too quickly.

In addition, online slots typically contribute 100% towards the bonus wagering requirement. This is a significant detail because most online casinos assign a specific contribution percentage to each game type.

Table games, such as blackjack and roulette, often contribute only 5-20%. Live casino games, jackpots, and scratch cards aren’t usually allowed to be played with bonus funds at all.

What should players look for when choosing a slot for their bonus?

The first thing is the contribution rate, as you want a game that contributes 100 per cent or more towards wagering requirements. That’s why slots are the natural choice if you want to make the most of a promotion.

Players exploring online slots on Bojoko can easily compare options based on RTP, volatility, and bonus compatibility, helping them find games that suit their playstyle.

Understanding volatility is especially useful here. High-volatility slots such as Dead or Alive II or Bonanza can produce big wins, but you might spin for a long time without seeing much return. Lower-volatility games like Starburst or Book of 99 pay out more frequently, so they’re better if your goal is to finish the wagering requirement.

It’s also worth checking RTP. Theoretically, a game running at 96 per cent RTP returns more over time than one at 94 per cent, and some casinos use adjustable RTP versions. Reading the slot’s info panel before you start takes only a few seconds and can save a lot of time later.

Finally, look at time limits. A single day to complete heavy wagering is unrealistic for most players. One or two weeks gives you space to play normally and still finish comfortably.

Slots nearly always count 100 per cent towards wagering requirements, unlike other games.

Do bonuses genuinely give players an advantage?

They can, but only when the terms are fair and realistic. A good bonus doesn’t have to be large; it has to be achievable. The best offers are the ones you can actually finish. That’s where clear terms and realistic targets make all the difference.

In the UK, regulators have pushed for that clarity, and it’s helped. You now see fewer hidden caps or obscure exclusions than even a few years ago. Bonuses feel cleaner and closer to what players were promised at sign-up, which is how it should be.

How do casinos balance attracting new players with bonuses while keeping existing players engaged?

That’s a great question, because it’s where many casinos struggle. Welcome bonuses get all the attention, but retention is what really matters.

Smarter casinos now design tiered or recurring offers, like free spin drops, loyalty boosts, or activity-based cashback. These give players reasons to return without feeling pressured. The key is consistency; players value reliability far more than occasional big offers that vanish after a week.

How are bonus rules changing, and what does that mean for slot players?

The regulations are getting tighter, and that’s a good thing. The Gambling Commission is introducing new rules that make promotions safer and easier to understand. From 2026, casinos won’t be able to mix different gambling products in a single offer, such as combining slots and sports betting in the same promotion. Wagering requirements will also be capped, meaning players won’t face rollovers of 40x or 50x anymore.

For slot players, this is all positive. Slots already fit neatly into fair and straightforward bonuses, and lower wagering limits make them even more practical. It should also mean fewer confusing terms and fewer hidden restrictions. In short, bonuses will be simpler, cleaner, and far closer to what players expect when they sign up.