From an article of mine published at Biznology yesterday:
Example the first: United Breaks Guitars is a rant from one musician, Dave Carroll, who dearly loves his Taylor guitar. I couldn't hope to relate the story in as entertaining a manner as he does, so watch the video to get the summary of what happened. This video has had 5,342,399 views today. That's 5 million. Five million. How much would United have to spend to reach that many people and engage them for 4:36 minutes a piece? Out of curiosity, and because in some reptilian part of my brain there lives a direct marketer, I tried to figure out what conversion rate Dave Carroll had achieved with this. I added up all the blog posts, Google hits, YouTube comments and ratings, and determined that 12% of those who viewed the video responded in some way. Any direct marketer with that kind of response rate would squeal like a little girl. At least I would, in a scaly reptilian way.Eva Lyford, Biznology Blog by Mike Moran, Sep 2009
You should read the whole article.