Not speaking for Google, but I'd also point out that newcomers and competitors can experiment with search (think ranking, ui, etc) in very interesting ways. For

Not speaking for Google, but I'd also point out that newcomers and competitors can experiment with search (think ranking, ui, etc) in very interesting ways. For all the teasing that cuil received, the did try something pretty interesting with the ui, for instance. I also know that competing on search is very difficult and expensive, given the computational demands, which is why new, good quality competitors is hard for us to come by.