Identifying a niche indeed is valuable for commanding higher rates. Niches also can be created by identifying special more value-adding aspects of even not-so-unique capabilities. It may be something that many consultants probably wouldnt recognize as a niche. For example, my rates (though not my salary) literally doubled over night when the small consulting firm I worked for merged into a major consulting firm whose status served as a niche.

Regardless, though, offering niche services wont matter unless you get the word out in resonating ways to the niches prospective market. Generally, those who get the work are more highly rewarded than those who do it.

Oh, and dont forget that the downside to a niche can be the related overspecialization, which narrows your market and can make your niche especially subject to market and technology shifts.