TL; DR FanDuel was sold for less than its liquidation preference, so common stock holders got nothing.
Then again, so much of startup culture actively conspires to make deal structure/cap tables/liquidation preferences opaque, because nobody wants to say "Hey, come work for this startup for 2σ under market salary and x% equity. Never mind that the equity will get crazy diluted and a liquidation event might get cleaned out before it ever gets to your end of the table. That is, if a liquidation event ever happens!" So I don't feel totally ignorant about not understanding it, just yearning.