Considering the explosive growth of social media, retailers are quickly expanding their social strategies. According to Compete.com, a leading Web analytics firm, Facebook had over one million unique visitors in April, and the Twitter craze is driving huge growth for tracking sites. Fast movers in April included tweetmeme.com (up 338% to 1.68 Million Unique Visitors), tweetdeck.com (up 69% to 915,000 UVs), twittergadget.com (up 56% to 100,000 UVs), twitpic.com (up 37% to 3.33 Million UVs), and bit.ly (up 53% to 1.81 Million UVs), according to Compete.

Several retailers are cultivating a strong presence on social networks to communicate and engage with their customers. With its 820,900 followers, Whole Foods Market ranks number 36 overall in number of followers as of June 7, according to Twitter tracker Twitterholic.