And just a fun side experiment idea: I'm curious how the IBM Watson User-Modeling service would stack up out-of-the-box against how you currently do things:
https://ace.ng.bluemix.net/#/store/cloudOEPaneId=store&servi...
http://www.ibm.com/smarterplanet/us/en/ibmwatson/developercl...
Could make for an interesting blog post if you have the time!