The latest search engine rankings from comScore indicate that consumers consistently choose Google when conducting online searches. For search marketers, this means paid campaigns and content strategies should cater to the search giant.

Americans conducted more than 16.6 billion explicit core searches in October 2010, with Google representing 66.3 percent of search share and fielding more than 11 billion queries – a 4 percent increase over September. Microsoft sites saw greater month-over-month improvements, handling 7 percent more explicit queries in October. Still, Microsoft represents just 11.5 percent of the explicit core search market.

Meanwhile, Ask.com, AOL and Yahoo sites all saw decreased share in the explicit core search market last month. They also experienced declines in total core search share, as did Microsoft.

Google was the only search engine to increase its total core search share in October. While the other leading search players, Yahoo and Microsoft, declined by 0.7 and 0.4 percent respectively, Google gained 1.4 percentage points, now representing 64.3 percent of the total core search market.

The steady gains of Google in spite of the Bing-Yahoo alliance may lead some marketers to question whether Google Instant is impacting consumers' search behaviors. If Google Instant is having a positive impact on the company's search share, it will be interesting to see whether Yahoo's similar Rich Search Assistant feature that is currently being tested can help improve its rankings next month.