The requirement for being eligible to withdraw or get something out of welcome bonus is really difficult these time around because after the bonus is given, and maybe you have to complete a 50 times wagering before you can withdraw and while wagering, you lose all that money, then it's just better than not even having the bonus. There's a local casino I use, they give cash back bonus, such as when I make deposits they give small amount or when I stake on a games they also give small bonus, I have observed that you can withdraw the money without any requirements but not all casino does give such bonus, they only give the one they can easily take back. These are all strategies to get more customers.
I also use one local bet company like that they give me bonus every week but I don't know how the Allocate the bonus their users but one thing I noticed is that if I deposit more in a week, the next Monday I will be receiving more also the same when I deposit low but the good thing bout them is that, once you bet on any game with that bonus and win, they will only remove the bonus amount you used in betting leaving the remaining amount for you, I don't care much about welcome bonus because I know that most casinos joke with gamblers with it, to me I don't see any sincerity in those welcome bonuses, it is too tasking, you will wager until you get tired and at some point you might lose, so what's the need for such time wasting, you just got it right, those are just ways to lure players in nothing more.