Twitter to start charging soon

Co-founder Biz Stone said the company is in the first phase of rolling out commercial accounts that will entice business users to pay for premium services like detailed analytics. After that, the company might move into building business-oriented application programming interfaces (APIs), creating a “commercial layer” over the social network. The commercial APIs would be out “later this year,” he said

via Twitter to roll out commercial accounts this year | VentureBeat.