I got to know the product at GameDev conference where Questcity made a quest to get to know all the companies around. That was a pleasant experience, I wish other conferences had this type of gamification to introduce key members.
Took a quest around old town of Tallinn soon after - I've been living in Tallinn for years and they still managed to amuse me with some facts and things. Looking forward to the time when other cities around Europe get enough content to introduce tourists to their culture and history.