Humans are creatures of habit. When we find something that works, we do it again and again until neural pathways form and it becomes automatic. Whenever we have a problem, and we think about where we can go for a solution, our brain will explore the options we already know and trust. You want your customers to find so much consistent value from your community that it becomes their go-to. You give them the security of knowing there's always a place they can turn.
