Google has created a new module for the personalized homepage that shows you recommendations, based on your search history, your location and on the search history of similar users.
The module called 'Interesting things for you' features searches, web pages, and gadgets. The searches were previously available in Search History Trends and included the top gaining queries related to your searches. So the recommended items have two qualities: they are popular and related to your searches.
This reminded me of Amazon recommendations and the power of personalized recommendations. Of course, in this case, Google doesn't want to sell anything. It just wants to use the information from your profile for interesting things, and I'm sure there are more things to come in this area. After 'Suggested Google Groups', 'Recommended Google News', this is another recommendation system that uses implicit data collection (no work from the user).