Twitter ad system lets you shill automaticallySOne reason a lot of Twitterholics love Twitter is that there are no advertisements to interrupt the first-person human communication. Now TechCrunch editor Michael Arrington has found a German startup, Be-A-Magpie, that offers to pay Twitterers to mix ads into their status updates. The service sends tweets from your account, with your name and face plus their 140-character advertiser's message. I love watching Arrington smolder over the idea, because he's right. The Internet was built by people trying to get away from this sort of thing.