Celebrities have been recently earning large amounts through endorsements in blogs and microblogs, such as Twitter. According to wired.co.uk website, the Office of Fair Trading (OFT) has already launched an investigation into a PR firm engaged in paying celebrities and bloggers to advertise goods of their clients.

Arnie Gullov-Singh, the CEO of ad.ly – firm engaged in connecting companies with celebrities who endorse products on Facebook, Twitter and other websites – told Business Week that Snoop Dogg and Kim Kardashian can earn from £2,000 to £6,500 per tweet.

He noted that in the past celebrities were afraid of tarnishing their image, but now they agree to earn money easily.

The statement issued by OFT says that such advertising does not comply with the rules for fair trading. In the United States, the Federal Trade Commission requires that Twitter endorsements include the words “ad” or “spon” to mark their status, wired.co.uk writes.