I play on Party Poker and in my opinion bluffing is just different online, it still exists.

You can set your computer to raise so that the bet is made instantly as if there was no thought...that can look like a bluff. Or you can play cards that offer good concealment then play passively if you draw something good so that when you suddenly bet out on a card that shouldn't have helped much it looks like you're bluffing but you're not.

Online it comes down more to what went on earlier and how people bet pre flop. That can often be an indication of a bluff. For example if they didn't raise pre-flop with a premium hand that is just bad play, so you can assume if they didn't bet out then that they don't hold certain combinations of cards. If they suddenly start betting big on a scary board that suits premium card holders after you have indicated weakness, it can sometimes signal a bluff.

You're right about playing tight and sniping though, as long as you introduce a bit of variety sometimes that is probably the best strategy in the looser games at the lower stakes tables.