Let’s get this straight, out of the gate: you stand a fair chance of losing money in this game.  Casinos are massive monuments of opulence for a reason – they almost always win.  No matter how well you play, it’s still a game of chance that is slanted ever so slightly in the house’s favor.  It all comes down to your skill level, your bankroll, the amount of risk you’re comfortable with, the quality of games you play, and of course, chance.  If you can balance all these factors, the theoretical long-game advantage a successful card counter can hope for is between 0.5% and 1.5%.  This doesn’t mean player can’t have more success on a given hand.  However, in the long run, a card counting blackjack player can expect to win about 1% of the total sum of his “action”.
The bottom line: if your average wager is $50 and you play 60 hands an hour (one hand a minute, that’s pretty easy to do playing online blackjack even accounting for breaks) you might expect to make about $30 an hour.  BUT!  Never lose sight of the fact that this is a game of chance and you’re never really in control.