How did li.st grow?

@bjnovak according to Tech Crunch, since your release in late 2015 li.st now has over 150,000 users who have created over 250,000 lists. I'm interested to hear what you and your team did from the marketing side to achieve such explosive growth?
  1. 1.
    How much of a emphasises did you put on celebrity endorsements? And how effective have they been for you overall?
  2. 2.
    Did you run any paid advertising of any kind?
  3. 3.
    How big of a role did PR play in your growth this past year?
  4. 4.
    What other marketing channels are you using at the moment?
  5. 5.
    What was the main challenge you faced when marketing li.st and how did you guys get around it?