The Federal Communications Commission has ruled that marketers can send a one-time mobile text message confirming users' opt-out requests. That should close a legal loophole that had sparked several class-action suits and left many companies wary of using SMS-based marketing strategies. "This isn't spam; it isn't robo-dialing. It's a permission-based marketing model. The FCC's ruling recognized that," said Michael Becker of the Mobile Marketing Association.