It's a pretty clear fold. Litterally the only thing you beat is air. What to do if you call preflop? Fold: it's a simple, no set no bet. But I really like to raise in this spot, unless you've noticed that the limper defends often. Maybe raise a little bit more though, you definately don't want a call. After the flop, cont bet fold, just like you did.

The eights are obviously only margianlly ahead here preflop, but thats not at all the issue. You have three chances to win some money here: preflop, on the flop with a cont bet, and you can double up if you hit a set. So unless he's a calling station, or loves to limp aces or kings early, I'd bet every time here.