This name has become very popular in Finland, and its popularity can be attributed to the fact that this is the Finnish name of the character Pippi Longstockings. It sounds cute on little girls, but I can't imagine a grown-up with this name. It's very hard to imagine someone with a PhD named Peppi! It's very girly and youthful.
It's a real groovy name for my hamster but now that I've called her that it would feel a bit weird to have a friend by that name. Oh well, I guess every name is funny if you think about it!