Personalized News: A Market Overview is a good review. As Greg, founder of Findory, indicated, implicit way of personalization is still working in progress. The best approach will be a combination of implicit and explicit.
On the explicit side, users need to get good ROI: return of investment. Users spend certain amount of time to specify their own preference. They need to be convinced this investment is really worth it.
Following is copied from http://glinden.blogspot.com/. From search perspective, I have not experienced any personalization yet from Goolge.
In Google’s Q3 2006 earnings call, Google CEO Eric Schmidt emphasized personalization of information in Google’s mission and future plans.
We believe that people’s information and the information they want to receive … needs to be accessible when and where they want it for them in a very personalized way.
The interesting thing is that this approach to having your information personalized is a benefit not only for the user who can continue to refine and target information … but also for businesses who want to know they are spending their money in an effective and targeted way.
As we continue to innovate and bring out … new products, we’ll also continue to … improve the experiences, bringing the most personalized and targeted information to people, which is ultimately our mission.
[We] provide access to the world’s information … [and] organize it in a very personalized and targeted way. That benefit drives the entire cycle of Google, and it’s fundamental.