Awesome post John and thanks for mentioning Ad.ly! Here are some "behind the scenes" numbers to help answer your question: 1. We did over 22,000 endorsements on Twitter in 2010 2. All message were 100% disclosed (per FTC guidelines) 3. We did not have one single negative event that we (or our marketer) had to address 4. Re: paid media, our campaigns average well under a $1 CPC ROI 5. Re: earned media, we had campaigns in the hundreds that became trending topics on Twitter More observations... The largest mainstream media publications average between 300 - 400 clicks per Tweet. A celebrity like a Kardashian or Beiber, will avg well over 18,000 clicks per Tweet. Compete.com shows celebrity names (aka keywords) as the large majority of direct search terms for Twitter. I think the bigger question is... If the history of advertising is reaching the intersection of audience and message (a la newspaper, print, billboards, radio, television, internet, etc) and celebrities are creating the messages that people are paying attention too -- is this not an opportunity to create a relevant and compelling media experience? Derek Rey VP and co-founder of Ad.ly @d_rey