The latest data from comScore showed that clicks on ads placed on Google didn’t change much from January 2007 to January 2008. Clicks were actually down 12% from the last three months of 2007.

Clicks on Yahoo! ads also fell 3% from the fourth quarter, but it was Google that got all the unwelcome attention, including a stock price dip to about $450, down from about $740 in November.

What is going on?

BusinessWeek quoted UBS as saying in a research note that “unless there’s a problem with comScore’s data, the most likely scenario is that ‘advertisers are simply bidding on and buying fewer keywords.'”

eMarketer senior analyst David Hallerman also said that an economic slowdown would likely mean less online shopping for consumers, and therefore fewer clicks on the ads that direct them to retail sites.

Via eMarketer