farmboy - 1:00 pm on Oct 29, 2010 (gmt 0)
More ads = more options for visitors.
It's the same basic concept of AdSense using those arrows in ad units where visitors can click for more ads. But instead of relying on a visitor to click those arrows as with AdSense, the ads are automatically shown in this new ad unit being discussed.
I don't know how often visitors click on those arrows, but this new type ad unit might be something AdSense should consider.