It depends on your bitcoin bankroll size. The more coins you hold, the higher the impact extra interest feature will have over your daily income. That is why I compared it to another investment platforms.
Wheel of Fortune free spins are just an extra bonus.
As far as I know, you only need to have at least 30k satoshi to start earning interest from FreeBitco.in, which can increase your bitcoin amount. Besides buying FUN tokens that can give you more benefits, you can use some bitcoin to play multiply. You don't have to hold FUN tokens in FreeBitco.in but you can also hold it in Binance and earn more rewards from the FUN tokens. Besides that, FreeBitco.in gives you free Spins and sends the links in your email.