Slingshot SEO has released the largest click-through rate (CTR) study of the last five years, striving to give marketers a better understanding of what to expect in terms of website traffic as it relates to search rankings.

“Conducted over the last six months, our study will help marketers better define the value of SEO to a brand’s budget,” explains Evan Fishkin, head of research and development for Slingshot SEO. “By establishing a reliable CTR curve, you have valuable data in estimating the amount of traffic your website will receive.”

Based on a sample set of 324 keywords, the Slingshot SEO study reveals an 18.2-percent CTR for a No. 1 search engine rank and 10.05-percent CTR for the second position. CTR for each position below the fold was observed to be below 4 percent.

The last comprehensive study using actual traffic data, rankings and search volume was conducted using leaked AOL Search data in 2006. That study, however, occurred before recent algorithm updates, a new user interface, increased mobile search, the addition of social signals and blended SERPs with videos, news, places, images and shopping results.

To be considered for the study, a keyword phrase had to have a stable first-page ranking (1-10) in the search engine ranking page for a 30-day period. Because more changes are expected as search evolves, including changes Google is considering to its user interface, this study will be an ongoing project that will compare with future search engine ranking pages and also compare with other CTR studies.

Full study results are available on the Slingshot SEO website.