Check it out: 'Tweetstakes,' 'Tweetaways' Pay Off for Chickdowntown.com

Sometimes Reed also posts tweets that advertise exclusive Twitter sales. A recent one, for example, told followers to enter TWITTER20 upon checkout to get 20 percent off the store's vintage collection for one day only.

While bringing brand awareness to the company, Reed says the Twitter promotions and sweepstakes also build sales.