synthese - 7:03 pm on Feb 4, 2013 (gmt 0)
We tested the 320x50. The test lasted about a week. Very low CPM. We had a it sitting like a leaderboard at the top. We pulled it and place a 300x250 right down at the end of the content and that did way better, so go figure.
In my case, the G rep said that was really surprising and that people had a lot of success with the 320x50... so... who knows. You can only test.
@sgod thanks for that.