One thing he needs to have figured out is: how are you going to get people to come to your site. Since he has a background in sales, he should already have a so

One thing he needs to have figured out is: how are you going to get people to come to your site. Since he has a background in sales, he should already have a solid plan for how to get visitors and turn them into users. If he doesn't that is a huge red flag. You can have the most awesome value proposition ever, but if you don't know how to get users (not just traffic), then it doesn't matter at all. Most people underestimate how hard it is to get people to use stuff on the internet. Also, if you gave us a general idea of the market or general area the idea falls under, we could provide more specific advice. Good luck!