Erm, aren't those exactly opposed?

"Drift along" as long as you are profitable is the definition of sustainable, no?

"Attracting too much audience" is anathema to sustainable if you can't maintain reliability or profitability in the face of the flood.

That's because they don't charge content creators; as it's a pay to play only platform, they make money from the individuals that subscribe to you. The amount you charge is up to you, though they only list the minimum once you have an account.