news feed was defended based on the increase in usage (hits, etc.) of facebook. I'm guessing usage dropped during this whole experiment - it would certainly have been mentioned otherwise.

As for revolutionary, a lot of apps were trying to do related things - most notably the books apps - you could buy a book that a friend was reading and the app maker would get a cut from amazon. To me, it seems a very small step up from there.

I disagree that it is a "very small step up" from the book application. There's a pretty big problem, I think, with web applications being pretty much unable to communicate with each other or with other types of services. Facebook is attempting to solve that with the most "complete" system created so far, Beacon.

I think we'll see a lot more like it in the future. With extremely good privacy controls, no doubt.

Conceded. Cross-site communication is a problem I had not thought of.

I'm still not sure what their novelty is given how doubleclick's cookies working across different portals were being talked about during the dot-com days. I thought Beacon was implemented using the same technique plus direct http calls.

Is there some deviousness I do not know about?