I’d like to cancel this standing order clindamycin phosphate for ringworm Costolo — who had sold Feedburner, an advertising-based blog publishing service he founded, to Google for $100 million — had no such doubts. By his second month on the job, he had helped persuade Williams to green-light engineering positions to build Twitter’s first ad unit, which would become the «promoted tweet» — the cornerstone of Twitter’s business today.