I really wanted to love Neeva, and became a paid subscriber as soon as I heard about it (a couple of months ago). Tried it for a few days and then gave up and cancelled my subscription. The product was simply really bad - search results were significantly worse than other (freely available, ad supported) search engines, the AI was very limited, and the personal search features were broken, authentication was broken and their support didn't even commit to fixing it in the future. In retrospect, I think Neeva had a cool mission, but the problem wasn't, or wasn't only, that they couldn't convince users to give them a try, but that even once they did convince users to give it a try the product was just not there.