Marketers are returning – or even rushing back – to the practice of employing search ads, according to the latest data from Efficient Frontier.  Efficient Frontier found that spending on search ads increased by 24 percent in the second quarter of this year compared to the same period in 2009.

That’s good news for the search industry, and arguably great news for Bing in particular.  Jack Marshall explained earlier this morning, "[T]he report found Microsoft’s Bing engine increased its portion of U.S. spend significantly in the past 12 months, growing from 4.1 percent in Q2 2009 to 6.4 percent in Q2 2010, representing a 54 percent increase."

Then here’s another key point: "Despite Bing’s failure to wrestle spend from Google, the report found that advertisers using Microsoft’s product are continuing to receive greater return on their investment.  The data suggests advertisers experienced 21 percent greater ROI using ads on Bing than they did on Google."

Of course, it’s hard for everyone to win at a single game, and since both Bing and Google succeeded in different ways, that means Yahoo wasn’t exactly looking competitive.  Efficient Frontier believes its share of spending dropped from 20.4 percent to 18.0 percent on a year-over-year basis, and on average, Yahoo offered just 75 percent of the ROI advertisers saw with Google.

Still, all three companies are doing well on the stock market this morning.  Indeed, Google’s up 1.38 percent, Microsoft’s up 1.29 percent, and Yahoo’s up 1.00 percent right now.

The Efficient Frontier report could definitely translate into positive news for everyone as we head into another season of earnings reports, then.