[aeturnum]

Right now you have short descriptions about the sites in the alt text. Consider adding an expandable section for each link that has: the short description from the alt text, maybe a "for people who like..." (or "for people who don't like...") pointer for users to understand the philosophy of a resource.

I think the problem with users coming once or twice is that taking the time to understand and try a resource is a lot of work. With only the bare links, they have no way to use their previous experience to judge the other resources without another significant investment.

You could also ask users to vote "works for me" and "doesn't work for me" and then display those votes when a user registers theirs. You could also use those votes to track the utility of each link to users.