Twitter didn’t do much for Ricardo Guerrero at first. In March 2007, the new tool was getting rave reviews from social media aficionados at the South by Southwest interactive media festival in Austin, Texas. Guerrero considered this tiny new tool du jour very limited, at least from his perspective as a marketer of refurbished Dell products. No one was in control. Conversations started in the middle and trailed off to nowhere in particular. If he wanted to direct messages to “targets,” they were free to “unfollow” or “block” him out.