Tribecca, CO just sat down full stacked.

1. He raises to $4, I call with 44 on the button, blinds fold.

2. Flop [9s][3c] he bets $6 into a $9.25 pot, and I call.

3. Turn comes , he checks and I bet $15 into a $20 pot.

This good/profitable against an unknown?

What if turn was ? Should I even be calling this flop?

And if not should I even be calling with 44 here as I don't think they stack off when I hit a set all that often.

Calling the flop is OK occasionally. It is better to do it against someone you have seen check-fold the turn before though. And I take back my drawtastic remark...the flop is pretty dry, save the flush draw. The ace is good because many villains will fire again with an ace and check if they don't have an ace. The turn card brings a lot of new draws which is bad for you. Still, you might as well take a shot since you can't call a river bet if you check behind.

If the turn was a your likelihood of taking it down on the turn is somewhat higher.

I wouldn't even consider what will happen if you hit a set, since that is so unlikely and you are obviously not getting odds to chase a 2 outer

Bottom line is that this may or may not be +EV. It depends on the villain, which you know nothing about.

Do this when the board isn't two tone and have all sorts of high straight draws.