Following the transition of Yahoo's organic search results to Bing, many marketers have been waiting to see how the combined powers of Microsoft and Yahoo will fare against Google in the search market. The latest search rankings from comScore indicate SEO strategies should still focus on the search giant, but Google saw minor losses where Bing-powered results were on the rise.

By comScore's measure, Google declined by 0.4 percent in terms of explicit core search share in August. Additionally, it dropped by more than a full percentage point last month over July with respect to total core searches. Nonetheless, Google fielded the majority of consumer queries in August accounting for roughly 10.3 billion searches (65.4 percent and 60.5 percent of explicit and core searches, respectively).

Google's losses seemed to be Bing and Yahoo's gains. Yahoo sites gained 0.3 percent in the explicit core search market and 0.9 percent in the total core search market, while Microsoft sites increased their shares of these markets by 0.1 percent and 0.2 percent. Yahoo and Microsoft sites accounted for a combined 28.5 percent of explicit core searches and more than one-third (33.8 percent) of total core searches. Together, they fielded 4.4 billion queries in explicit core search and 5.8 billion queries in total core search.

Google sites clearly maintain the lead in terms of consumers' queries, yet the gains demonstrated by Yahoo and Microsoft indicate that marketers may want to more carefully consider optimizing their paid search campaigns for Bing in light of the upcoming holiday shopping season. As Brafton reported earlier this month, search marketers can now migrate their accounts to the Microsoft adCenter. Transitioning accounts as soon as possible may be a wise move as 13 percent of marketers say they don't use Bing at all, and the paid search switch from Yahoo to Microsoft is anticipated to happen as early as mid-October.