Since Yahoo closed their Site Explorer, does anybody know how all of these Backlink checkers are pulling their results? I want to provide a similar service as part of a package to our clients, but as far as I can see, the only alternatives are: Google (site:domain.com) - not good enough Bing (site:domain.com) - not good enough Yahoo (site:domain.com) - not good enough A lot of these backlink checkers are pulling quite a lot of results, which none of the aforementioned services (Google/Bing/Yahoo) are returning with those queries. So does anybody know how they're doing it?