Seriously, thanks for the heads up to this paper, which I’d missed. I’m highly skeptical of collaborative filtering approaches to news (I’ve personally been underwhelmed with Google’s attempts), but I know better than to argue with Google over numbers! I am glad they’re attacking the challenge of item churn head-on, since that is indeed a huge difference between news and ecommerce, at least for recommendation approaches that extrapolate from past user logs. And, while I may not like the approach in general, I do respect the researchers’ attempts to incrementally improve it.