Clicks, conversions, and Christmas

Online advertisers have noticed that CPCs tend to increase during the holiday season and have asked us why. We turned to Hal Varian, Google’s Chief Economist, for an explanation:Many advertisers track their average cost-per-click (CPC), but what really matters for the bottom line is the average cost-per-acquisition (CPA): how much you have to spend on advertising to make a sale. The third factor