A recent piece in the WSJ profiled the use of Twitter by several companies in the fashion world, that I think highlights a transformation in customer/business relationships:
Ms. Bearman is one of several executives who tweet on behalf of luxury fashion brands, masking their marketing in a Carrie-Bradshaw-esque life-stream. Dozens of labels now have a presence on Twitter, the benefits of which are seen most clearly during New York Fashion Week. Tweets come fast and furious during the shows, providing designers with instantaneous feedback from attendees and giving the events a much bigger marketing stage, albeit a virtual one.
When starting a new company or store, opening accounts on Twitter/Facebook/etc should be on the top of the to-do list.