This was the first Cambrian House business model. I saw two problems. First, you didn't know what to do with your metrics -- if changing a button from green to

This was the first Cambrian House business model. I saw two problems. First, you didn't know what to do with your metrics -- if changing a button from green to blue caused signups to go from 20/day to 25/day, which number indicates how much customer demand exists? Second, as pg pointed out, startups rarely get very far before figuring out there's actually a much better product for them to build that's about 70% different from their current one. At best, the site no longer is evidence of interest in the new product, you have to start it over. If you've taken pre-orders (the only way to reliably gauge interest) you may be committed to building what you sold.