Communicating means taking an idea that's in your head and putting it in someone else's. That requires overcoming several layers of resistance.
Basic elements, like body language and tone, make up most of a face to face message. It's primal. You can tell whether someone's attacking you. You don't need their words.
We're wired to spot threats: negative interactions have a lot more impact than positive ones. In relationships, without at least five positive interactions for every negative one it will deteriorate. How many people do you tell when you had great service? Terrible service? A little bit of negative can outweigh a lot of positive.
Once you've established you're not a threat, you still need to break through the barriers of comprehension (What do you mean?) and ambivalence (Why should I care?).
Attention: If you have a reputation for valuable messages, they are more likely to honour your message with their attention.
Messaging: Articulate your message in a way that is crystal clear to your intended audience. It's irrelevant whether anyone else understands it.
Superconducting communication: Trusted confidantes. There are a few people who really get you. The filters are off. The resistance to communication can drop to zero. You understand. You care. You have enough shared history, in-jokes and context that they already know what you're thinking.
In those cases it doesn't take much to communicate much more than just what's said. Then again, there's always money in the banana stand.