Thanks for your write up. After my own failed attempt I came to the conclusion that any product based primarily on aggregating products that others sell is a failed model. You are a middle man in an already thin-margin industry and are competing directly with shops (who are incentivized to have customers come directly to them and bypass you) and other aggregators. It would be better if you became a drop shipper and sold the products yourself. Much more control, and the audience you were building with ads would have stayed.