Since the beginning of the site? Too many to count.
Blurtit has been through various iterations, and the site we're using now could also be considered a work in progress.
Our community is growing by about 600 new profiles each week at the moment. As a site, we also get over 5 million visitors a month, so overall it's pretty impressive!
We've still got work to do in terms of organizing feeds, creating a more "buzzing" atmosphere, and making it easier to discover interesting Q&A. We're all pulling together though, and I think we're close to a big breakthrough
