(Newser) – American celebrities are raking in up to $50,000 a month for tweeting on behalf of brands. A single shout-out from 50 Cent or Snoop Dogg, for instance, can earn them $5,000, finds the Sun. The pay-per-tweet model is now heading across the pond, and UK celebs won't be required to use "spon" or "ad" to mark paid tweets. A government official urged the country's famous folk to tweet responsibly: "If people don't reveal a tweet is paid for it could undermine fans' trust," he warns. (Click here to find out how not to be a jerk on Twitter.)