Expertise and authoritativeness of a site increases its quality. Be sure that content on your site is created or edited by people with expertise in the topic. For example, providing expert or experienced sources can help users understand articles’ expertise. Representing well-established consensus in pages on scientific topics is a good practice if such consensus exists.
Security. With all the malware and viruses online, Google has decided to include security as one of the factors in web site ranking. This covers two important issues: One is the SSL certificate mentioned earlier. Another is insuring your website and servers are up-to-date and free of infection. You'd be surprised at how many bots are poking at websites looking for vulnerabilities. Google will pull you out of search results if your website is compromised (although you can ask for re-ranking once you clean up your site).
Word of mouth communications and peer-to-peer dialogue often have a greater effect on customers, since they are not sent directly from the company and are therefore not planned. Customers are more likely to trust other customers’ experiences. Examples can be that social media users share food products and meal experiences highlighting certain brands and franchises. This was noted in a study on Instagram, where researchers observed that adolescent Instagram users' posted images of food-related experiences within their social networks, providing free advertising for the products.