No Mans Sky has sold over 10 million copies. I'll let you do the math. They are still basically an indie company as well.

AFAIK, there is no in-game microtransactions or anything, so basically retail sales I suppose? The studio is relatively small (indie-scale) last time I checked, and the launch was pretty big and I'm sure they pulled in a ton of money, even though as always on the "vocal internet" the launch was a huge failure, they still sold a lot of copies. "Just" 1-2 million copies would go a long way to fund a small passionate team. The all-time peak for simultaneous players on Steam (PC only) was 200K, so I don't think 1-2 million copies sold is far off as a minimum.

It did well commercially looking just at steam stats, not to mention the other platforms. It seems like alot of that was used to turn it around to save their reputation to keep going not only with one game, but to make sure the next isn't "stay away" labeled even it is "wait and see" for many.

Small studio, don't have to generate a lot of sales to keep them afloat. Updates push visibility and generate new sales. Obviously, they need new projects to keep them afloat in the future.