Emotions are a strong motivator of human behavior. This is even true on the web. The more that ranking signals continue to evolve, the more significant the role that emotion-motivated actions play in search engine optimization. After all, one of our primary focuses as SEOs is to develop content that makes everyone who sees it want to share it and say wow. And saying wow and sharing are prompted by emotions.

Search engine signals like links, social shares, clicks, and even the way that search quality raters view a site, are strongly tied to the emotions that a website, and the content of its individual pages, evoke from its visitors.

What makes a user click? What makes a user create a link? What makes a user share something? What makes a search quality rater check the "trusted site" box? It's all emotion.

And so it follows that in order to influence, persuade, and motivate users to click, link, and share, we need to understand some things about emotions and how to bring them about through the content that we publish online.

In 1980, Professor Robert Plutchik created his wheel of emotions:

The wheel identifies eight basic emotions each with a corresponding opposite: Joy -> Sadness, Trust -> Disgust, Fear -> Anger, Surprise -> Anticipation

And while I recognize that the emotional aspect of SEO isn't a revolutionary concept, I'm surprised by how often it goes overlooked. Further, much of the content that does focus on generating an emotional response is limited to the basic emotions.

For example, pictures of kittens might make some people happy. Contests fill people with anticipation. Endorsements and positive reviews can make us feel trust. Press releases can be surprising. Op-Ed pieces with which we disagree can make us angry or even disgusted.

Admittedly, developing emotion evoking web content can be quite challenging. It requires some basic understanding of psychology, as well as, an understanding of the people in your online networks and the visitors to your site(s).

And so, if I could provide any useful advice or takeaways here, I would suggest that you spend more time thinking about and understanding your online audiences.

What makes them happy? What makes them sad? What types of things evoke a strong enough emotional response to get them to click (a relatively low emotional response), to share (bit higher response), and to cite or link to (an even higher response) your content?

And don't limit your consideration to subject-matter only. Think about how the form that your content takes can influence emotion. As the say goes, a picture can be worth a thousand words.

It's also worth noting that human emotions are volatile. Before you decide to "pick a fight," you had better try to anticipate the foreseeable consequences. While being controversial can be a great thing for SEO, there is often reputational collateral damage. While you might be inclined to believe that "all publicity is good publicity," you might not be able to anticipate the harm you might cause to your brand, your reputation, or your relationships.

Finally, as web-based communications technologies continue to evolve to help us better express our emotions online, it is very likely that search engines will increasingly take more sophisticated emotional expressions into account when delivering search results. In the wake of F8 and verbs, and with the transition to an HTML 5 web, it seems that a more emotional web is inevitable.