How do the sign-up bonuses work?

I've read that Bodog.com is the only site that offers your bonus upfront... so that makes me curious how does the 100% bonus for Full Tilt Poker work since I plan on putting my money there.

From what I recall, they just add 10%. They used to ad 5% to every deposit, but that changed I think. It's been so long... What I do know is that they are my favorite as far as coming through on bonuses. For instance, I went to cash out $600 a week ago from BoDog. They had a "problem" posting the withdrawal and decided a check would be the best method. Because I was inconvenienced, they offered me 20% bonus on either those funds or my next deposit. I took it on those funds. I played the 120 once through on blackjack, lost only $20 of it, and cashed out for $700. Not a bad deal from where i'm sitting, and the best kind of bonus - not 100x play through garbage.

FT releases yer bonus $ 10% at a time. Eg- if you deposit a hun and they offer a 100% percent bonus, they will release $10 of it when you reach that earning level.

Ultimatebet accrues yer bonus dollars every time you play, 10 cents for every UB point you earn.