I'd say this not only applies to Ecommerce but every website out there. The "Niche" is where you want to be in the long term. Outside the "Niche", the margins are thin and the competition is fierce.
I'm finding Local Niche's each and every time I go out. There are so many "golden opportunities" out there at the local level.
For example, I just went to the Sawdust Festival in Laguna this month. Wow, the local artists really have a great thing going. And you know what? Someone needs to help them bring their products to an International market. And, I have just the person in mind to assist them. :)