A social signal is a human interaction metric gained via platforms like Facebook, Twitter, Instagram, Linked In, and Reddit (as well as countless other social media sites available today). This includes likes, dislikes, comments, shares, and follows, representing affiliation to a brand, whether it be positive or negative.
As more consumers have joined the multitude of social media channels, social signals have become an important part of organic search engine rankings. Whilst Google has said that social signals are not a direct part of their ranking algorithm, those websites showing on page one tend to be those with the highest share volume. The research from Cognitive SEO below shows the link between social interactions and rank.