Leave out uninstalled applications from history
When you own an Android device for over 6 months, all recommendations are becoming stale. You've installed, used, and then uninstalled apps.
And then they pop right back up in your 'you should try this' list.
Make a difference from all other recommender systems by recognizing the history of users.
Oops! I mistyped url. anidb.net - japan animation movies database.
It give great recommendations, based on algorithms like "k-nearest neighborhood" and "Pearson Correlation" http://en.wikipedia.org/wiki/Recommender_system. But now recommendation system stopped, because of high load on server.
Idea from anidib.org. Recomend only apps unrated by user.
When user install, rate and uninstall it must be hidden from recomendation.
But how about application updates. application can be improved in next release...
Martin Krischik commented
An “un-installed Applications” list would be nice. Currently I keep one manually but an automatic one would be even cooler.
And this list could then be used for more intelligent suggestions.