I was seeing this earlier:
But only for the bare domain http://serverfault.com, everything else was working, including https://serverfault.com/questions, https://serverfault.com/users, etc. The "File Name:" portion would randomly change to "questions" "favicon.ico" and "" (blank) when refreshing.
The blocked page wasn't coming from our web filter, it ...
I have worked with Chernoff a few times on getting these ads fixed :) I just pulled a report for the impressions served over the last week- the open source ads served over 3000 impressions, so they're not broken, they just have a low Share of Voice (SOV). I will increase the SOV and ask that you keep me posted.
I personally don't know too terribly in-depth about the specifics, but in a nutshell, it tries to show you the most relevant job listings considering what it knows about you, which includes location, what site you're looking at, and which questions and technologies you seem to be interested in based on what questions you've looked at (see here).
Because imgur.com returns an http status code of 200 for that image, there's really no way for us to detect when an image is no longer available.
SvenW's action to edit the offending community ad was the proper one until its author can upload a new image.
The ads for other Stack Exchange sites have always been on the sidebar ads. Usually they're for programmers.se or one of the beta sites, which have much less intrusive colour schemes.
Additionally, we should be seeing a lot more relevant ads because the Community Promotion Ads have been extended to all SE sites.
I know I've seen some of the ads over the last few days, on a regular basis. But to try and track their stats for a day or two, here they are.
As of 3/14/12 12:45:00Z
Created: Jan 2 at 15:52
Clicks per day: 1.49 (106 total)
Created: Feb 25 at 1:42
Clicks per day: 2.33 (42 total)
Created: Feb 28 at 21:21