For example, {HEAD ~ the analyzed behaviors} may include {TAIL ~ the item purchases}, item rentals, item viewing activities, web browsing activities, and search histories of the users 
For example , { HEAD ~ the analyzed behaviors } may include { TAIL ~ the item purchases } , item rentals , item viewing activities , web browsing activities , and search histories of the users
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH