The hard part is NOT building such a site. The hard part is getting users. It's almost impossible to get funding for something like this without first demonst

The hard part is NOT building such a site. The hard part is getting users. It's almost impossible to get funding for something like this without first demonstrating that you can get users where "demonstrating" means "already has a lot of users and, more important, growth in users". (There are a few people who could get funding for this project before such a demonstration but those people wouldn't be asking this question on hacker news.)