Online tells...

Playing online and playing at a LIVE table require to very different strategies. I find online to be a lot harder to make accurate reads on opponents.
*Something one needs to do in order to improve their game is, take NOTES. For online use the make a note facility provided by the site. It will help you in the long run as it makes remembering previous experiences a lot easier.

With online, there aren't many means of gathering information only betting patterns and the chat/comments window. So here are a view things I have been noting:
Players whom comment "donk or poor play" - I'm sure you have come across many of them. These are novice players. They mainly play the premium hands, pretty tight and can definitely over play big pairs. Their biggest weaknesses are their lack of understanding of pot odds and they often fold a DRAW.
-Losing to a DONK will put them on tilt!
-They have convinced themselves that AA or KK will always win them the hand.

Watch the chat window, observe where chats between to players who know each other discuss matters like previous hands or tournaments or past experiences. Use these Q & A to get an understanding of their experience levels and whether they are regulars.

>Something I have tried countless times, I'm sure you have too. MULTI-TABLING.
- This is definitely a sign of some skill as its difficult to monitor more than one table at a time successfully. What I have noticed though in their playing style, is it becomes relatively tight - they will waste little time on marginal hands. In my opinion poker takes a lot of focus and unless they are good at multi-tasking they will make a few unusual mistakes when attempting more than one table.
*So, browse the lobby and identify those opponents.

I don't know how true this theory is, but the size of the chip stack definitely is an indicator of skill. For some reason better players tend to accumulate more chips than others.

In summary, in order to be a successful poker player both online and live, you have to remain focused and vigilant at the table all the time, even when your not in the hand - your goal is then to be analysing your opponents moves for a spectator view point....