In July 2013, we were in the middle of the YC batch, trying to figure out how to get our product off the ground. Then we had office hours with Paul Graham, and he gave us this advice:

"One of the most common types of advice we give at Y Combinator is to do things that don't scale."A lot of would-be founders believe that startups either take off or don't. You build something, make it available, and if you've made a better mousetrap, people will beat a path to your door as promised. Or they don't, in which case the market must not exist.

Actually, startups take off because their founders make them take off. There may be a handful that just grew by themselves, but usually it takes some sort of push to get them going. A good metaphor would be the cranks that car engines had before they got electric starters. Once the engine was going, it would keep going, but there was a separate and laborious process to get it going." 

We immediately took his advice to heart. Flew from San Francisco to NYC and started doing gimmicks to attract and recruit customers in Washington Heights, one by one. Though this was not scalable, it put us in an uncomfortable but necessary position to be face-to-face with the customers to better understand what they want and don't want.