I believe I am a profitable Poker player, simply because I have never made a deposit on-line, ever, have built several Bankrolls from Free-rolls, and even in the Live games I can and do sometimes win the occasional game.
The thing that stop's people being a profitable player, are themselves, they lose their temper, and go on "tilt", or are overstretching themselves and their
bankroll, trying to achieve what in most case's is impossible, and that is to become a Poker Superstar making millions in prize money.
You only have to play in a huge MTT game to see the numbers for yourself, I have played On-line where there were over 10,000 entrants in a MTT game with an $11.00 buy-in, I didn't pay that because I won a seat in a free-roll satellite game, but the point is there could only be one winner and Thousand's upon Thousand's of loser's, I was one of them! But what have I lost? not the $11.00 buy-in, that's for sure!
Being sensible in your approach to the game, playing purely for fun, accepting defeat when it happen's, because it will happen more than your Victories, and respecting your Bankroll, because there is no such thing as a bottomless Bankroll, all help me to be Profitable.
When the fun Stops, STOP!