There are two threads on the topic of a possible bug with Microsoft adCenter. It seems like some advertisers are reporting seeing a major drop in the impression reports displayed for their search ads. A Microsoft Advertising Forum thread and a WebmasterWorld thread have reports from two advertisers.

Here is one report:

In the Microsoft Advertising Forum thread, a Microsoft representative did reply telling the person to call in. The person did and was given information stating this is a bug, but the forum rep said it likely isn’t a bug. Let me quote them.

Microsoft’s forum representative replies:

So who is right? Microsoft or Microsoft? Oh wait?!

Of course this is a bigger issue now, cause Microsoft gobbled up Yahoo and now powers about 30% of the search ads in the US.

Forum discussion at Microsoft Advertising Forum thread and a WebmasterWorld .