Using Twitter for Customer Service

Next time you have an issue that you need to contact customer service - Twitter may be more effective.
Pretty much all the major companies as well as many little mom & pop stores can be found with a twitter account now. You can follow the companies to find out about their latest sales/promotions but you can also tweet at them for customer service questions.
The best way to do this is:

• Look for the small blue check mark which shows the company twitter account is verified. This applies mainly to the major companies that can have double accounts also claiming to be the same company.
• Be brief and clear  - you only have 140 characters to describe your issue.
• Include a hashtag. A hashtag is when a "#" is in front of a keyword, ie: #bestbuy. This is so the keyword comes up in a search.

I know of someone who recently used this approach when their cable was continually being knocked out and the company actually responded with tech support being sent out the next morning and a one month credit on her bill.

American Express has a twitter account solely for questions @AskAmex, which I often tweet questions regarding rewards and even international fees. Each time I've gotten a response within the day and I was even given the name of the person who is currently tweeting to me.

Has anyone else used this approach and found it to be useful?