After reading the second paragraph, itjust seems like you tie Blippy/Foursquare together via api's and aggregate the data. Is there anything I'm missing?
Sorry if this comes off as negative, it's really meant as constructive criticism. I went to your site and I'd love to see more thought put into explaining why, as a user, I want to 'earn points' or 'recommend' on Spibby when I can do it on a ton of other sites (for exampleI'd probably use yelp right now). Some sort of analysis of what happens when the service gets huge (why is it valuable to me? Why does my contribution make a difference? What is it working towards?) could be very helpful in making people interested :)