Organizations take a macro approach. When they want to interact with a group of people; they send a message to them all. That isn't very effective. Impersonal e-mail gets a limited response. Some organizations even know this, they just cant think of another way.
Most amateur (unpaid) community builders work in the miro. When they want to reach a group of people, they message a few of them. They have conversations (proper ones). They pry a few of the group into their way of thinking. Then they pry a few more. Then they talk to more and reference the people in that audience they already have. They genuinely earn their trust.
It's a process of gradually working through and with the audience you want to reach. Target specific people, establish a connection and work your way gradually through the target audience. It gets easier and quicker as you become more respected. Soon, others will do this for you.
Think about this next time you want to approach new people to your community, or persuade existing members to do something. Macro interactions are far quicker and easier. But it's the wonderful world of the micro that will succeed.