That statement makes no sense at all! Online I see way more hands, can play four tables at once (you can play more but, I seemed to lose concentration on more than four), and you have thousands of players at once compared to maybe 100-200 people on a good night.
I agree with loquacious. When playing online i can literally hunt down and target weak players with by using a super hud. This tells me how many games they've played, average buy in, average win/loss profits, type of games they play, type of player they are, bet frequency on every street. After a while you can almost gauge exactly what kind of range a player is opening with from what positions and what they are likely to to do on what kind of boards. If im playing a Sng one look at my HUD tells me exactly who understands ICM and who doesnt, thats all i need to know to target these players.
I woulod not and could not consider even sitting online without a super hud. Firstly though i would reccommend reading and understanding ICM, then get Sng Wizard to analyze, your position/ hand range and optimal push fold strategy. With practice this then becomes second nature and you no longer find yourself in situations of uncertainty.
Then upload all your hands to be analysed and pick them apart. Find out what your winning and losing edges are, eg what are the BBs you most go broke with, what marginal hands your pushing with, what positions your losing plays are, etc.
I will take this info any day over live tells