Chock-full of beautiful graphics (powered by robust crowdsourced data), the 2015 Ranking Factors Study is a must-read. A few morsels from the study: - The continued lessening of the importance of on-page keyword use - A high correlation between links and ranks - Low relationship between type of top-level domain (TLD) and rankings - Social shares and the correlation with positive rankings - Engagement metrics that correlate lower bounce rates with better rankings Get the full study at Moz