I think you may be confusing viral marketing for a pyramid scheme. Given, pyramid schemes are a form of viral marketing, but exponential growth through sharing

I think you may be confusing viral marketing for a pyramid scheme. Given, pyramid schemes are a form of viral marketing, but exponential growth through sharing is necessary without being sufficient. In this case it works out fine for both parties. I signed up because I was interested in beta testing and socialcam gets to choose their potential beta testers by how social they are. For what it's worth the system may not be very effective yet. I have one referral and I've moved from #4000 to #600