Black Jack can be addictive, but remember that online BJ at UB uses an "endless shoe". Where you get an edge in BJ is from a finite amount of cards. You either use one deck, or multiple deck shoes, either way the cards are finite. With a set number of cards, after a few hands have been dealt you can see whether alot of small cards have been dealt (leaving more face cards to come - giving you an edge over the dealer). However, with an endless shoe this isn't possible and your meager 1-2% edge over the house disappears.
You can definitely win a couple bucks, but as it averages out, you will most likely be in the losing circle. Get out quick, if you're ahead.
The Elimination Blackjack Tourneys are pretty fun though and since you actually play with the House cards against other players, you have a far better chance in taking home some cash. IMHO I would stick with the BJ tourneys.
Good Luck at the Tables!