I eventually saw the ad while I was logged in. It appears that ads are only shown for a percentage of page impressions, so even if I purchase all of the availab

I eventually saw the ad while I was logged in. It appears that ads are only shown for a percentage of page impressions, so even if I purchase all of the available impressions, my ad won't be shown for all pageviews. I suppose this makes sense, I just wish they made it more clear.