Do any retailers have experience setting up a Twitter account specifically related to notifying customers about special deals? I've read about it, but don't know a small business that does it. I know Dell does it for its online factory store. Seems simple enough.

I have set up social networking campaigns for small and multi unit merchants and Twitter is a huge component in getting your message out. A chain of dollar stores that I work with tweets out when new shipments come in and it has been very effective at driving traffic to the stores. I'm big on the social media and it's a great way for small retailers to reach out to new customers.