It's September, which means that job descriptions and resumes are flying fast across the Web. This is not new to the interactive industry, or to search engine marketing (SEM). What is new is where all of the search talent has gone. A year or two ago, search engine marketing employees were simply recycled throughout the three hundred or so competitors. We all know of a few search media managers who are now on their third or, (gasp!) fourth SEM. Today, however, the trend is to ditch the search gig for good and venture into the world of start-ups, leaving the space suffering from massive brain drain.