I agree with the above. I'll also add that it helps to know something about the opponent. You don't want to triple barrel into calling stations. It helps if you have at least seen them fold a hand post flop, preferably on the river.
By firing 3 barrels you are basically telling the story that you made a good hand on the flop. You are value betting the flop, and turn, AND river because that hand is still so good. There is a chance your opponent doesn't understand any of that. You don't want to 3 barrel bluff noobs.