Chucklefish's procedurally generated space-themed RPG Starbound has sold more than one million copies thanks to its inclusion in the Steam early access program and the company's own pre-order efforts. Starbound is currently an early access game on Steam, allowing consumers to play an early beta build of the game while developers make wild and drastic changes. Selling for right around $15 via Steam's early access program, players have been enjoying the game since December 4.
Chucklefish also ran an early funding promotion, offering players willing to spend $15 (the starting base price to get a copy of the game and access to the beta test) all the way up to a $2,000 tier that gave players special perks and in game honors. That proved to be highly successful and generated millions for the company even before the Steam early access launch.
Even if all of those one million copies sold for the low-end of the tier (we imagine many customers paid more via the pre-order page), that's roughly $15 million in profits generated for a game that hasn't even been released yet.
You can get in on that action by visiting Steam, or by checking out the Starbound pre-order page.