Many advertisers expected the CPC (cost per click) prices to go up after the Yahoo / Microsoft adCenter transition was complete.

One advertiser said in a WebmasterWorld thread he CPC prices “soared” by 40%. He said:

We are seeing a 40% increase in click costs on average since late September on existing AdCenter campaigns. Our transitioned campaigns are seeing a similar percentage increase when compared to what we were paying with Yahoo.

The costs are so out of control, he has pulled and pause his campaigns with adCenter. He said:

Have you seen the same? Please take our poll and ask your friends to take it as well:

CPC Costs After Yahoo / Microsoft TransitionMarket Research

Forum discussion at WebmasterWorld.

Update: There is a good white paper on this at SearchFuel.