Facebook is the social media site of choice for many US online retailers, judging by an August 2008 study by Internet Retailer and Vovici.

Nearly one-third of responding businesses said they had a Facebook page, compared with 27% that had a MySpace page and just over one-quarter that had a page on YouTube.

A September 2008 study by Rosetta (formerly Brulant) that focused on the top 100 online retailers in the US found that 59 had a fan page on Facebook, up from 30 in May 2008. Among the 29 who added Facebook pages since that time were Best Buy, Toys “R” Us, Kohl’s and Wal-Mart.

“Social media sites continue to be an important source of community connection, and savvy retailers are reaping the benefits of Facebook’s rapid extension into new demographics, such as Gen X and seniors,” said Adam Cohen, partner with Rosetta’s consumer goods and retail practice, in an interview with eMarketer.

However, Mr. Cohen said that retailers should guard against casual attitudes toward their Facebook presences.

“It’s important that retailers don’t just slap up a page because everyone is talking about Facebook. An effective presence requires that you carefully consider what your customers are looking for, what you would like to communicate, and what role a fan page should play in your overall online strategy.”