“Most reports cited an increase in search spend anywhere from 13% to 29% year over year, partially driven by an overall increase in click volume. Kenshoo noted that click-through rates on the Yahoo! Bing Network were 29% higher than Google.
Marin found that Yahoo! and Bing are continuing to show solid growth in aggregate click volume, with an increase of 9% year over year, as well as a 9% increase in click-through rate.”
http://advertising.yahoo.com/blogs/advertising/search-engine-marketing-remains-key-growing-part-digital-183612184.html
Toms Blog on Life and Livingness