A comScore (NSDQ: SCOR) report indicating a decline in Google’s January click-through rates helped send the search giant’s stock similarly downward earlier this week. Aside from shaking up investors, the comScore report also fed fears of that the online advertising market was tanking as well. Having seen the way the numbers were interpreted by the industry, comScore CEO Magid Abraham has weighed in and issued a memo explaining what its report did and didn’t mean.

As comScore’s January 2008 qSearch paid click report showed, Google experienced a 7 percent sequential decline vs. December ‘07. It also showed flat annual growth in paid clicks for Google (NSDQ: GOOG). Moreover, the number of paid clicks per Google search query fell by 8 percent from December to January - which led some to conclude that consumers are clicking less on search ads, possibly indicating a reduced desire to keep up their purchases in the face of a sputtering economy.

Although comScore doesn’t completely dismiss that view, it did say that its report did not directly support it. Quite the opposite: Since Google has introduced a “quality score” designed to weed out low-quality ads, there are likely to be less ads in general. Furthermore, comScore adds that fewer low-quality ads means that users need less clicks to get what they’re looking for. comScore also points out that if there were a serious decline in click-through rates, there’s no reason to think that the users would single Google out, despite its dominance, and leave click rates for Yahoo (NSDQ: YHOO), MSN, AOL (NYSE: TWX), Ask and others relatively unaffected. Secondly, comScore says that click rates don’t necessarily correspond to a weak economy, as a similar situation occurred earlier last year.

• Google Slammed On Ad Fears, Click Throughs; Stock Off 35 Percent From Highs