Personalized search yields dramatically better search results

Greg Sterling at Search Engine Land, in his article "iGoogle, Personalized Search and You", quotes Google VP Marissa Mayer as saying:

[Personalization is] one of the biggest relevance advances in the past few years.

Personalization doesn't affect all results, but when it does it makes results dramatically better.

See also excerpts from a few recent articles by Search Engine Land columnist Gord Hotchkiss in my earlier post, "Personalization, Google, and discovery".