I called them yesterday morning and asked "Is the 300% signup bonus non-cashable, or is it fully cashable?" The operator's response, "it's cashable".
So, I dropped in $100, had $400 to play with, and proceeded to play single-hand Blackjack Surrender at $5 a hand. The WR is $8000 (about 1600 hands).
I started out by losing my first ten hands in a row. If I had been playing for a sticky bonus, I'd have been broke by this point. It turned around though, and by hand 61, I was back at $400. By hand 275, I was up to $500. The next 600 hands fluctuated, then turned south, and at hand 960, I was down to $385. I climbed back up to $500 at around hand 1400, end ended at $457.50 when I had met the WR.
Because I'd made $8000 in wagers, CasinoOnline comped me $8. I took the remaining 50 cents and dropped it into a 5 cent slot machine, making $5 on my last nickel.
So, if it's not a sticky...
Casino Online: $300 bonus: +$370
Something out of nothing to date: $1,820
Hey, I've got enough for a single table 6-player WSOP satellite! (Nope. Not gonna happen.)
(June 21 note: no, it wasn't sticky. The $470 withdrawal just showed up.)