Brafton recently reported that marketers switching their campaigns from Yahoo to Bing have until October 25 to transition their accounts, but new data from Efficient Frontier may make marketers consider whether they want to invest in paid search on portals other than Google. According to the digital research firm’s 2010 Q3 U.S. Digital Marketing Performance Report, Google is the “early winner” of the Bing-Yahoo ad integration.

The report indicates that there is an overall increasing demand for search marketing. Last quarter, year-over-year ad spend was up 19 percent and search marketing expenditures rose 6 percent over the previous quarter. Additionally, ROI grew 8 percent over last year, demonstrating that marketers’ campaigns meet consumer demand.

It seems marketers are most heavily relying on search giant Google to get their ads displayed to prospects. Google’s share of paid search spend rose from 75.8 percent in the second quarter of 2010 to 77.9 percent last quarter. Google’s click share also rose to 76.3 percent in Q3 2010. Meanwhile, Efficient Frontier says Bing’s share of ad spend can’t clearly be determined; while Microsoft picks up Yahoo’s paid search spend and traffic, it’s difficult to distinguish natural versus forced shifts in the market.

Looking ahead, the firm believes Google will see even more gains in Q4 2010. Plus, with the holiday season ahead, the Efficient Frontier predicts search spend could grow in the range of 15 to 20 percent next quarter.

Marketers planning their 2010 Q4 paid search campaigns should try to take advantage of Peak Week, reported by Brafton last month. During Peak Week in early December, paid search ROI traditionally spike.