I read given below article and we need to think out on it. http://www.blindfiveyearold.com/is-click-through-rate-a-ranking-signal
CTR is a ranking signal. Google is taking user behavior aspects like CTR, bounce rate, time spend on the page for their algo. But one thing to remember is its not one factor that effect ranking. Google consider several user behavioral factors and overall site performance to decide your ranking.