You can get a sense of the power of the site by visiting the site and clicking a keyword on the left. For example, if you click on Startup, you find:
are all considered highly relevant to the term “startup”.
As the site runs, it will get better at finding great content.
All of this technology comes from Tony Karrer. If you have ideas on how to improve the site or want to do something similar, I know that Tony would like to hear about it.