Attention of the Crowd

I'm reading what Phil Wendly and Doc Searls are saying today about Attention and Intention, and it dawns on me what the real value of a real estate listing might be (or a Craig's List). It's not so much in linking a particular buyer and seller - that's a one-off deal.

But what if someone captured, and made available, informtion on what was being eyeballed! What listings are being viewed the most, what are the common characteristics of those popular listings?

Now that insight could be extremely profitable in various different ways.

It's kind of like the Attention of the Crowd ... er ... Intention of the Crowd ... whatever.