In Google Reader, posts whose status are changed to read by pressing the ‘mark all as read’ button don’t count towards the read count in the trends page. This is most likely to affect you if you have switched off the option under settings (Click on settings at the top right, option ‘In expanded view, mark items as read when you scroll past them.’) so that you can quickly scroll through the items then click mark as read once done reviewing that page of posts (which is more akin to how Newsgator works). If you want the trends page to show read counts you have to enable the ‘In expanded view, mark items as read when you scroll past them’. [...]