Or you can make a custom extension with an increment_view_count operator that receives an object id and increments the view_count value, and put it on the full view template. And if you want to rank the most popular in the past X days, then you'll have to create a new table with columns contentobject_id, view_count, and date. The increment_view_count would increment the view_count column or insert a new row (if it's the first hit of the day) and you'll have to create a fetch function or an extended attribute filter that fetches the most viewed objects in the past X days.