The model of Spotify in particular - paid tier alongside a free tier with ads - seems like the simplest sustainable solution I see. Having paid features is the most obvious way to make money, but you want to enable adoption as much as you can. It's the same idea as companies dangling "free trial" in front of you at every turn - in a competitive environment, you want to remove barriers for users to try your product or service. This is essentially the idea of a "loss leader" for a grocery store, or any business really.

I'd be happy to open a PR for this, but I'm not sure exactly what code needs to change. default_source_map.rb and source_map_utils.rb seem like candidates, but I'd appreciate guidance

If I can find some time, maybe I can help pitch in somehow.

Ethereum is the leading platform for initial coin offerings or ICOs. A project can use an ICO to raise millions of dollars, peer to peer from investors around the world.

He was the second of his family to make an offering to Delphi (after recovering from his illness) of a great silver bowl on a stand of welded iron

For Midas too made an offering

Gyges sent many offerings to Delphi