My son lured me to Hive with a value proposition, although I didn't think of it in those terms.
I was spending a lot of time on Twitter. Got a pretty good following. Engaged regularly with some people. Then my son said,
"Why don't you go on Steemit? You can do everything you do on Twitter and there is free speech there. No central control. Also, you can earn coins while you do it."
Coins were not the main lure.
I think people leave for a number of reasons. One is that upvotes cost money--maybe that's the problem. Maybe 'likes' shouldn't cost money. Maybe we should have a dual system under the posts...non-monetary likes and monetary upvotes. Then people could simply like, or vote. Engagement would likely grow. Comments would likely proliferate. These also could be liked or upvoted. I think that might spiff things up. Make this more like a traditional social networking platform. Money would still flow. It just wouldn't serve to slow down engagement anymore.

