Communities and groups on social media are an environment where people look for recommendations and solutions from peers, not from brands. This is precisely why they have high trust and, at the same time, low tolerance for advertising. There are two approaches for companies. The first is expert engagement in other people's groups – answering questions without pushing an offer, through which a brand becomes known thanks to being useful. The second is building your own community of customers or experts, which is more demanding but provides direct access to people without dependence on reach. A company's own group needs clear rules, an administrator and a regular reason to come back. Without one, it goes quiet. It is worth monitoring mentions in groups even when the company is not active in them.
Source: thinkwithgoogle.com
See also: Social listening, Comment moderation, Employee Advocacy.