I’ve played a total of 17 ten-player tables in the past 5 days over at PokerStars and have a total record of one 1st place finish, one 2nd place, and one third place. The buy-in per game is $3 (+ $0.40 to the "dealer"), so I’ve invested a total of $57.80, and won $30 ($15, $9 and $6 for each of my top 3 finishes). Due to the buy-in/reward ratio, I need to win at least 1 out of every 5 games I play in, in order to actually turn a profit. My current success rate is about 1 in 8.5, which is admittedly still pretty far out.
I’m finally beginning to understand what it takes to win these things, owing to some no-limit hold ‘em strategy videos I saw over at ThePokerBay. The overall technique is based around patience, and a folding rate of around 90%. Yes, that means that in a game of 40-50 hands, you will generally play only 5, folding everything else. This explains why professional online players can manage 6 games simultaneously, because more often than not, all they need to do is click the "FOLD" button and move on to the next table.
I doubt I can hit the magic 1:5 win rate without putting a whole lot more time and effort into this, but it certainly is nice to try.