I had this branch a little earlier, but I'll reiterate here. The main reason Hisptamatic didn't gain the following Instagram did was because it lacked a social element. I bought it when it first came out, and while it was fun for a little while, lacking a social element kept me from coming back to it. Instagram was free, similar, had a better interface AND was a social network. By the time Hipstamatic added their social component, it was too late.