In live (or so called Brick & Mortar) poker, the money isn't yours until you've left the table.
In online poker, it isn't yours until you've cashed out.
The other week, on Wednesday, I "found" an unclaimed bonus of $25 at one place I frequent. By Thursday I had doubled that to $50 after being In The Money at Sit&Go's and winning a $10 heads-up game. By Friday, well, I was back at $25... But if I hadn't lost the $20 5-seater tournament and/or a $5 ten-seater tournament I would or could have doubled it yet again to $100. Could'a, would'a, should'a. But I don't think I have to point out the Rounders quote. Yes, of course I have it on DVD.
And for no particular reason (or so it seems) I got a $15 bonus at Partypoker (use registration code MARTYPARTY for a $25 sign-up bonus at your first deposit). Great! Because my account there had $4.75 on it which I could use for absolutely nothing. Smallest Sit&Go entry fee was $5, minimum buy-in at cashgames, yes, $5. Now I have a bankroll I can use again. I hope I'll use it wisely.