I didnt met alot of players that shows their hands, specially in the
online poker. I think some of them could use it for strategy, but you have to be sure who you are fooling and what you want to archive with your acts.
Its so rare an online player to show his/her hand. In other case, when you play live, you are showing your hand just from respect sometimes.
I think its not good to show your hand, just because if you stole the pot and show your hand, your opponent will learn more for you and what decisions you take in some situations and positions.