Here's a rather interesting fact I discovered:
Computers configured with Windows 7 do not display ads, even sponsored ones.
I accidentally stumbled on this today while shopping for a new laptop. I tested my site on the new gizmo only to see that my ad sections were all blank.
At first I thought there was something haywire with my site but when I loaded up other WP based sites that are prime, I realized the same thing is happening to them.
That's a major setback as new computers (including some cellphones) are not being sold with MS Windows 7 pre-loaded and pre-configured.
Haven't figured out how to bypass this. Anyone has any suggestions, please share them.