They can also be given away as a no deposit bingo deal, where you get free spins just for registering without having to make an initial deposit, although these are fewer and far between. This in itself may seem a bit strange especially when welcome bonuses have gotten bigger and bigger over the years but is not necessarily a bad thing.
In bingo, free spins may be given as an additional plus aside from the welcome bonus, although it is become increasingly frequent to find that free spins are being offered as the only offer for new players.
Free spins offer have become much more popular in recent times amongst bingo sites as well as slots and casino sites, especially those geared towards mobile bingo or mobile slots.