Good news for Microsoft and marketers who advertise on Bing – the search engine’s ad clicks are steadily increasing. According to Efficient Frontier’s Q2 2010 Search Engine Performance Report, the clicks and views for ads on Bing are rising, while declining or holding steady for Yahoo and Google.

The report relays that Bing’s click share, stable over last quarter, has grown 36 percent over Q2 2009. It seems this annual growth comes at Yahoo’s expense – Yahoo has declined from 20.1 percent of click share in Q1 2010 to 19.4 percent in Q2 2010, and the search engines has seen click share loss of 9 percent over Q2 2009. Meanwhile, Google’s click share remains fairly constant, with slight growth to 75.6 percent in Q2 2010.

It seems that ad spend on the search engines is closely correlating to these clicks. Bing has a year-over-year increase of 56 percent in ad spend, and quarter-over-quarter growth from 6.1 percent of spend share in Q1 2010 to 6.4 percent this quarter. Yahoo’s spend share fell from 18.7 percent last quarter to 18.0 percent in Q2 2010, demonstrating a year-over-year loss of 12 percent. Meanwhile, Google holds steady with a spend share of 75.6 percent.

These diverse results leave officials at Efficient Frontier cautiously optimistic about the upcoming Microsoft/ Yahoo merger. Since the two search engines are currently performing differently and offering different ROIs to advertisers, the firm predicts the two companies should reconsider their position on forcing advertisers to place ad bids on both Yahoo and Bing.

While the powers of Microsoft and Yahoo combined may offer a solid alternative to Google, the numbers don’t lie and it seems ads on Google are still marketers’ best bets for catching consumer clicks. In addition to Efficient Frontier’s reports of consistent click and spend share for the search giant, recent search market data from both Hitwise and comScore indicate that most online searchers choose Google for their queries.