[hobbsmann]

I tend to 3-bet the flop a lot these days HU (which might or might not be optimal) mainly as a way to balance my play as I'm putting in a 3-bet in position a lot with the worst of it. Thus the times I have a good hand I will often 3-bet as a way to both gain credibility for future hands as well as extracting more from the current hand.

To expand more on the idea of extracting the most money from a play by 3-betting on the flop, your hand will often look more like a draw and will encourage people to call you down. When up against better competition the flop call/turn pop so often represents a big hand that people will start bet/folding the turn more against you, where if you had 3-bet the flop you might have ellicited a calldown from them.