You will have a close customers base and they may very well end up being your best customers. They will help with a profitable growth for your business.

I guess if you offer services or products which are also available on the local market, it will affect business on both sides. Some businesses are better off local, due to the personal contact you have with the people, a better feeling and experience of service.

For selling, you need to be cheaper online, so someone will give up service for price.

Hope that helps to get your discussion starting. :)