School's in session,
to Yahoo's glee

Yahoo's share of search ad impressions and spending were up during the third quarter while Google leveled off in both categories, reports ClickZ.

The findings come from a study by SearchIgnite and RBC Capital Markets.

They found search marketers are increasingly turning their dollars to Yahoo, raising share of media spending by 7.8 percent over the second quarter. Spending on Google's search ads rose just 0.8 percent.

That brings Yahoo's share of the search spending to 20.4 percent, a dramatic rise from the 8.5 percent it held in Q2. The increased spending is attributed to the launch of the Panama ad platform and the subsequent squashing of bugs in that system.

Google's ups and downs are pegged to the school year, with search impressions dropping as schools quit for the summer, then going back up as students returned.

School is also a likely culprit for the drop in Google's CPM rates and a rise in Yahoo's CPMs.