What are some successful case studies of growth hacking?

We can considered Dropbox's referral program, which significantly boosted user acquisition, and Airbnb's Craigslist integration, which rapidly expanded their user base.

The Tinder story is a fun one.. it's in Andrew Chen's book Cold Start. They basically brute-forced the first few thousand users. There's more to it, but they threw dope parties on college campuses and made everyone install the app to get in.