Originally Posted by RDB
A lot of players have trouble switching between live and online. They play very differently. Live tends to be more passive and slower, while online is more aggressive and there's a lot of players changing in and out. It's difficult to get reads when people look alike and you only have a name.
Online poker is more difficult and requires more skill to beat than live poker for any given stake. For example, 10-25NL online is roughly equivalent to 200-500NL live in terms of the skill required to beat the game.
Tracking software, HUDs, and other simulators, calculators, and tools can certainly help, but only
if you put in the time to learn to use them properly -- they won't help at all just by installing them, and applying them incorrectly can make your game even worse.