PageRank and link popularity is a bit like going out into the street and asking everyone who the best scientist is â€” you are going to get the obvious names: Albert Einstein, Stephen Hawking. Theyâ€™re popular answers. Teoma looks within the topic. It finds the authority sites within the topic related to “scientists” and then asks “Who is the best scientist?” Chances are, Teoma is going to come up with names you have never heard of before, but are actually much better answers. It gives you the specialist answer instead of the popular answer. Another difference with Teoma is that it is keyword-dependent. So when you type “blue widgets” into that search box, it pulls the community together and conducts a local search which refines and finds the authoritative sites on that particular subject.The model of organizing the Web into topical communities and pinpointing the authorities (pages that have garnered a lot of inbound links from reputable, topically-relevant pages) and the hubs (those pages that link to a lot of reputable, topically-relevant pages) is an important model to grasp (read more about it in Mike Grehan’s paper on topic distillation), because I predict that all the major engines will become keyword-dependent over time. If you grasp this concept now and are picky about the sites you garner links from and link to, then you’ll be doing a lot to futureproof your SEO.