Average Time Spent on Websites Based on Site-Category

Content websites seem to be the place where people hang out the most times. In a study of how time spend on the various websites have changed over the years (between 2003 and 2009), content websites seem to have gained the most, though communications(email) seem to have lost time to accomodate social network. Here is the average time spent per month and growth since 2003:

Content websites : 6 hrs. 58 mins (+88%)
Communications : 4 hrs. 54 mins (-8%)
Commerce : 2 hrs. 40 mins (+26%)
Community : 3 hrs. 1 min (N/A)
Search : 57 mins (+111%)