Create content and use tactics that help to keep them connected with your brand, even when they are not actively engaging with it. One of the most effective ways to boosts engagement is through Newsletters. This will keep them up-to-date about your latest products and discounts, major sales that they shouldn’t miss or any changes you make with regards to the terms & conditions of your service.
In brief, we are inclined to go along with someone’s suggestion if we think that person is a credible expert (authority), if we regard him or her as a trusted friend (liking), if we feel we owe them one (reciprocity), or if doing so will be consistent with our beliefs or prior commitments (consistency). We are also inclined to make choices that we think are popular (consensus [social proof]), and that will net us a scarce commodity (scarcity).