What's your target audience? Everyone who has internet? Seriously? You must be bonkers.
You can't seriously be suggesting that I'd opt to choose your site instead of a local one, merely because there's just a crapload of crap from everywhere of the world which pretty much clutters the whole plainfield for every player in the market of crapmania.
Why would I upload a 1$ picture when there's no users to speak of? I mean, the site itself has no indication of how much people is using it. So if I'm a potential seller who wants to sell his crap, why would I opt a site that shows in no way how much users it has (if it's not public knowledge that the site has a lot of users).