The production covers the history and lasting effects of China's decades-long one-child policy, drawing partly on the history of co-creator Nanfu Wang.

While the deal doesn't represent the biggest payout at Sundance, it caps a flurry of Amazon acquisitions. The company was the most active at the festival, buying a Mindy Kaling movie, an Adam Driver political thriller, the turn-my-life-around comedy Brittany Runs a Marathon and Shia LaBeouf's self-referential Honey Boy. Amazon was determined to snap up titles that were either critical hits, showed promise for commercial success or both, and it was willing to spend tens of millions of dollars in the process.