Mainline churches come directly or indirectly from the medieval church, and medieval or pre-modern communication was highly relational. In its own low-tech way, the medieval church was networked. People created and shared knowledge and shaped their practical theology or their spirituality by sharing stories...
The modern period changed that. The printing press distributed knowledge and allowed the Reformations to happen, but it also privatized reading... Reading was not done in community anymore, and that changed the relational nature of communication...
Social media changed that. It democratized communication, giving everybody access to all kinds of information. It also gave people access to the means of creating, sharing and collaborating on information.
an excellent interview interview with Dr Elizabeth Drescher, author of "Tweet if You Heart Jesus" here. I've just borrowed the book from our College library. more to come...