The world of online casinos is full of slots of all shapes and sizes. There is hardly a theme that hasn't been covered in at least one online slot and players can find games offering anything from one to several million paylines and ways. However, when it comes to Online Slots bonuses offered by casinos, it is quite clear some slots have the lead over the rest.

Popular Casino Bonus Slots

Although it is hard to tell why exactly, it seems that a few slots are by far the favorites in terms of Free Spins or free play offered by casinos as a part of welcome bonuses and other promotions. Big industry names and newcomers alike offer very similar online slots bonuses on one of the few regular machines and there are very few deviations from this rule.

NetEnt's Starburst, for example, is one such slot. If players are offered free spins as a part of their welcome bonus and the game isn't specified, the odds are the offer is valid for Starburst. Although it is a fairly simple and old game, this slot remains the absolute leader in terms of free spins' offers.

Other games players could expect to get their online slots bonuses include titles such as Gonzo's Quest, Aloha! Cluster Pays, Guns N' Roses, and Fruit Shop. All these are NetEnt releases with a moderate big win potential, which makes them a perfect choice for these types of promos.

Those who prefer games by other providers can also find offers containing online slots bonuses for games like Book of Dead, Tower Quest, and Gemix.

Why the Limited Selection?

With thousands of different slots out there, it is somewhat strange that most casinos only offer slots bonuses on about dozen or so identical slot machines over and over. Wouldn’t it be better for them to mix things up and make them more colorful for the players?

Online casinos would probably love to have a complete freedom when choosing what games they can offer bonus spins on. However, this potential is closely tied to providers and the games they make available for these types of bonuses. And, for the most part, these select slots have become standard when it comes to casino bonus slots.

Of course, from time to time, Game developers do offer free spins and free play for some of their new releases to hype them up. These promos are usually time-limited, though, while Starburst, Book of Dead, and Gonzo’s Quest continue to maintain their timeless positions in the realm of casino bonus slots.