[IncRnd]

I was a solver on a different team for the netflix challenge. Our team didn't win the grand prize.

I would have expected that a blog post would discuss how this was structured. Netflix contracted with innocentive.com, which is a website for solvers, and contracting to that website expanded Netflix's reach to a greater available pool of solvers. As far as I recall, all the allowed solvers for the netflix challenge _had_ to go through innocentive. I'm not sure if they would have been able to get the same level of improvement if they had not contracted with a set of potential solver teams like that.

The original challenge listing for Netflix is no longer listed at innocentive.com, but an industrious person may be able to find it on archive.org or somewhere similar.

[tomnipotent]

I don't remember InnoCentive being involved with the Netflix Prize in any official capacity, but I do remember the PR storm they launched after the prize was awarded to make sure they were mentioned in news articles about it.

[IncRnd]

I signed up for the challenge, through innocentive, in July of 2008.

It's entirely possible that as a new solver at the time I fell for innocentive's PR. The netflix challenge was actually the first I ever signed-up to work.

[rocqua]

Note, not just the original listing has been taking down, but also the data used in the challenge. I believe because a few people in that set actually got de-anonimized. But certainly because of privacy concerns.

I think the data is still kicking around somewhere in torrent land. I also still have my own copy somewhere, I think.

[Delk]

IIRC it had something to do with researchers being able to statistically identify Netflix users by using IMDB for comparison.

A Wired article from 2010 [1] suggests it lead to some legal liability risks for Netflix.

[1] https://www.wired.com/2010/03/netflix-cancels-contest/