A fan it is characterized by a special connection with a brand, product, thing or person. A fan is interested in brands, products or services, as well as well-known communities, interest groups or public persons.
However, in social networks a fan is also determined by how he interacts with the object followed. This can be done through fan pages, liking a certain brand or through communication in groups, forums and blogs. Fans of social networks are users and, at the same time, important influence factors for online marketing, especially if they (as influencers) transmit advice and recommendations to other users and thus contribute to publicize brands, products or services.
The concept of social networks is based, in some way, on the interaction of users. This happens many times when you click the "Like" button on a Facebook page, the "Follow" button on Twitter, or the "+1" button on Google Plus. Whether you are a fan, follower or influencer, the key factor is a form of interaction through which the agreement is indicated. If the special profiles of social networks have many fans, it is considered a solid group, which maintains a special link with these pages.
Marketers should refrain from buying fans, that is, spending money on a certain number of fans, since Facebook can examine these purchased likes by classifying them by region. It would seem rather doubtful that many of the fans of a German Facebook profile came from the United States, for example. At the same time, Facebook will notice a sharp increase in Likes. A legitimate method of collecting fans would be a competition, called gamification. Potential customers are given an incentive to join and become fans.
Usually, participation in these contests is subject to certain conditions. For example, pressing the Like button or sharing a message. The more content is shared, the more it spreads and produces coverage. The number of shares is indicative of viral content. For example, the exchange of memes is very popular. Other alternatives to collect fans can be call-to-action items on your web portal, in newsletters or, in general, in commercial emails. In competitions, the policies of the respective social network must be observed, because the incorporation of source code and images must comply with the rules of the network.
Importance for SEO
A characteristic of social networks is the interaction between the brand and the user. At least since 2010, when Google first used social signals as a ranking factor, interactions between users and brands are considered an indicator of certain user interest or the virality of content.
However, Matt Cutts backtracked in 2014, saying that Facebook Likes or Twitter followers are not used to set SERPs. 
But user interaction is likely to still take the top spot when it comes to the controversial topic of social signals. Maybe Google doesn't know exactly which social signals should be used as ranking factors and which ones shouldn't. At the very least, assumptions can be made based on several phases of testing individual ranking factors such as likes, shares, or comments. The fact is, social media is a important tool for online marketing, but even more important for long-term relationships with customers, since more than 40 million Internet users participate in social networks every day in Germany alone. And also the presence in social networks is considered an important signal for search engines. Even if these signals are not considered as a ranking factor, they are at least an indication of a certain level of activity on the network.
The higher the engagement of users, the greater the likelihood that search engines will notice you positively. Ultimately, many social media fans also cause more traffic and surely a higher conversion rate, because if a fan maintains a positive relationship with a brand, product or service, the return on investment values increase.