“Building an audience” on someone else’s platform is a recipe for continual butthurt.

This is exactly what was said when Twitter and Facebook and whatnot started. If your business is solely on someone’s platform, you’re at risk.

The proper, long term way to do it is to make a site, post content there and then post links onto social media while driving audience toward a mailing list or some other subscription that you control. It was only a matter of time that Twitter put the squeeze on and $8/month is just the beginning. I expect, over time social media will get to equilibrium of taking 30% of whatever the value of the audience is.