How our dumb bot attracted 1 million users without even trying

Three months ago, we released a modest chatbot that we thought could be fun to use in group conversations. The bot, which we called Roll, did one simple thing: It randomly selected a participant in the conversation as the answer to such pressing questions as "Who is the biggest flirt?" and "Who's calling the Uber?" and "Who has a crush on me?" (The answer to all of the above is you, obviously.) We did nothing to promote the bot. We just put it in Kik's Bot Shop and waited. After 10 days, we had 200,000 users.