New slot sites will always offer some kind of welcome bonus. This kind of offer is fairly universal to the online casino world, as it’s the quickest way to attract new customers. Welcome bonuses are usually a ‘cash match’, meaning that your first deposit with the site is doubled, or more.
These offers are usually shown in a format like ‘100% up to £100’, where the percentage is how much the money is matched and the amount is the upper limit.
In the case of 100%, a £20 deposit will get you £20 bonus money. However, these bonuses tend to have some kind of wagering requirement, so it’s worth checking the terms. Occasionally, slot sites will also offer free spins or some kind of bonus game as a welcome offer.