I remember the first time I did a startup I was afraid to focus this narrowly because it might mean that we became a niche and my visions of grandeur

From Munjal Shah's blog:

This new site represents our key strategy for the year. Focus, focus and more focus. We launched Like.com in Nov 2006 and immediately lots of folks asked us if we were going to follow with generalized visual search, with visual search for dating (which we know doesn’t work), or with visual search for stock photography sites.

We decided instead to keep focused on shopping. In fact we didn’t just focus on shopping we focused on just on soft goods (clothing, shoes, handbags, jewelry, etc – things that are largely aesthetic and hence hard to linguistically describe – perfect places for visual search as they are places were text search falls down). Finally, we didn’t just focus on soft goods we picked 2 categories of products and just focused on creating the best user experience possible and the best business possible in those areas.
I remember the first time I did a startup I was afraid to focus this narrowly because it might mean that we became a niche and my visions of grandeur would not emerge. Now I realize that you first have to be really really good at one thing to ever be great at many. 2007 was all about focusing on one thing for Like.com

http://munjal.typepad.com/recognizing_deven/2008/02/likecom-live-wi.html