Refer-a-friend is pretty sweet. If you can find forums out there that will allow you to post your refer-a-friend link, you can make some points very easily. I was just saying in the chat-box today, I love signing out for the weekend or something and coming back Monday to a nice bonus chunk of points just from my referrals. 5% doesn't sound like a lot but if you can get a few referrals who are active, it can add up quickly.