In a world where nothing is free, it was going to happen sooner or later: sponsored tweets have come to Twitter. Ad-like tweets have been present since 2010, but the difference with the new tweets is that they are showing up in your Twitter stream whether you follow the brand or not, and users will not be able to opt out of seeing the ads (though you can make them disappear once they're in your stream by clicking "dismiss." Like billboards on the side of the road, ads on Twitter are now catching your eye, whether you like it or not. Read more >