Online and home games are two entirely different beasts (IMO).
Online you are very likely to be playing against multi-table players (MTP) or bots. The former will VERY likely to be using a Heads Up Display (HUD), which will capture and analyze data from every hand you play online. This provides a lot of information about your tendencies for VPIP (how many hands you play), raising, folding, etc. In fact, some sites will capture the information of every player on the site, and sell the database to HUD users for a fee. (Note that Playnow BC doesn't allow HUDs AFAIK, but just about every international site does)
The MTPs will also likely be using an AI GTO program (the bots will be doing this for sure, they are basically an AI GTO program), that will tell him how to bet in every situation.
Non MTP/bots might range from super splashy (exploitable but challenging to beat) to calling stations (unbluffable, but exploitable) to super nits (also exploitable). The problem is that by trying to exploit one of them, you will frequently fall prey to another of them, and when you add in the rake, the MTPs and the bots, it is not necessarily easy to crack that nut. Possible? Yes.
Note also that you will be playing WAY more hands per hour than in a home game, so expect to see a ton more bad beats. Note also that most of the tells that you might utilize in a home game don't exist online. You will have to rely on bet timing, sizing, and player history to figure out a player's likely holdings.
