How many people use Yahoo! Pipes?

Just a quick google shows about 750,000 results for site:pipes.yahoo.com

http://www.google.com/search?q=site:pipes.yahoo.com

I think there could reasonably be around three quarters of a million pipes created. I would hazard to guess that there may be half that number of all time registered users, so about 375,000. I can say that I have 50,000 users on 50 pipes on Twitter, so 1,000 users per pipe. That would make some 750 million Yahoo! Pipes users total. (I will be happy to be proven or disproven on any of these numbers.)