Our Yahoo SEM ads suddenly stopped showing. I checked my ad status after a week and noticed not a single click for the last week. Contacted Yahoo and they told me my analytics tag was out of date, which it wasn't! Then they emailed me yest 2 weeks after the fact and told me there was something else wrong and now they will be re-starting my ads from Monday. They didn't tell me what was wrong, and never apologized for putting the blame on me initially. We didn't even do anything! Has anyone else experienced such a problem with Yahoo SEM? How would you compare Yahoo to Google for PPC?