The main thing I learned is that fundraising is a non-deterministic endeavor. Just because you have everything you think you need, there is always a reason for an investor to say no. Most commonly, during the last attempt to fundraise, it was the unproven market. The only exception was a big data VC in NY, which believed in the market but didn't invest because we weren't all in the same city yet. And of course the couple of term sheets we turned down because of poor terms.

One angel who was a huge fan of the site told us that he wouldn't invest because there haven't been enough noticeable exits in the weather space. Go figure.