First off — the ad is still showing. If someone has a contact @ Mashable, it’d be good to send them a note.
Greg Yardley thinks that this ad is not served by the Adsense network but instead by Mashable’s internal salesforce and that they are simply using Google’s new AdManager product as their adserving solution. Digging through the tags, it’s unclear whether or not this is the case. The actual creative is hosted on the domain “pagead2.googlesyndication.com” which has traditionally been used to host Adsense creatives and ad tags. Google’s AdManager runs on a different domain — “partner.googleadservices.com” — but it is certainly possible that AdManager and AdSense share the same underlying static content delivery system. (someone from Google care to comment?)
This is an excellent example of the fact that URLs generally don’t provide enough information to identify who is delivering the actual advertisement on the page. In this Mashable/Google page, it is unclear — it could be Mashable’s internal salesforce selling the ad — or there could be some server-side integration between AdManager and Adsense and Adsense is responsible for serving this actual creative. Right Media suffered from many of the same problems — people would always yell at the Right Media Ad-Network whenever a creative hosted at content.yieldmanager.com was causing problems, even though that single domain was shared across 50+ networks.
The solution that we came up with @ RM was to start using DNS CNAME aliases when returning any and all content. A CNAME is a simple DNS record that simply says — “this domain name is an alias for this other domain name”. So for example, the domain “content.cpxinteractive.com” is an alias for “content.yieldmanager.com”. This way, if CPX was responsible for serving a bad ad the offending URL would be “content.cpxinteractive.com/ad.jpg” and not “ad.yieldmanager.com/ad.jpg”. CNAMEs allow central serving systems (eg, AdManager) to both hand out tags and return creative content tagged with an owner while still maintaining the same internal systems.