On Twitter, lines blur between celebs’ thoughts and paid ads

These celebs aren’t just writing about family cars and fashion choices for the heck of it. Stars can get paid big bucks — sometimes $10,000 or more per post — to pontificate about clothes, cars and movies in the 140 characters or less allowed per tweet. That adds up to about $71 per character. Twitter, which in its five-year existence has reshaped how people shop, vote and start revolutions, is now changing the business of celebrity endorsements. Just as Match.com and eHarmony pair up singles for dates, a growing number of startup firms are hooking up companies with stars who get paid to praise products to their thousands — sometimes millions — of Twitter followers. The list of celebs and the things they hawk is long and getting longer all the time. The endorsements range from subtle to blatant; the celeb pairings from sensible to downright odd.