An ad network that lets users profit from Twitter is making it harder to distinguish between autobiography and advertising on the social networking site.
"It's a shame," said David Silverberg, editor of DigitalJournal.com, about the Magpie advertising network.
"It starts to make people feel like they can't trust who they're following on Twitter."
Magpie, which is headquartered in Berlin, pays Twitter users for allowing it to send tweets from their accounts promoting the products of companies who have subscribed to the service, such as Expedia's New York travel specials and Apple's iTV.
Many appear to have been designed to look like real tweets.
They include a shortened link to the advertiser's website and sometimes a statement like "got mine couple months ago. love it!!!" or "going skiing next week" that resembles an update about the user's life.
Apr 20, 2009
The modern art collection of French film director Gerard Oury is going under the hammer.
It is made up of many major works which have never been put on the market before, including 80 pieces by French painter Raoul Dufy.
Archaeologists believe they are close to finding the tomb of Cleopatra and Mark Antony.
Russian scientist and winner of the Goldman Environmental Prize, Olga Speranskaya, says world economic downturn is likely to hurt the global campaign to save the environment.