I noticed this when I first joined the site. What are the likes on the pets, avatars, and posts for?

It's just to show that people like it. They don't really do anything except increase the number of likes, and there aren't achievements or anything for it.

lol oh.. gotcha it'd be nice for achievements lol!

I think the reason they don't have achievements for them is to prevent people from just going around begging for likes. You should like something because you actually like it, not because you feel obligated to for an achievement.

oh right aha