One day in 2013 at Pin Drop HQ, we noticed a sudden spike in downloads. There were no new press mentions or inbound links from social networks—it didn’t add up. Then we found the source. In Season 1, Episode 7 of the HBO series Girls, the character Marnie asks Hannah (Lena Dunham) and Adam (Adam Driver) to share their location with a ‘drop pin.’

Pin Drop was even name-checked in a book about the show…