We also did something that I forgot to mention in the article that helped us grow nationally before we had a lot of proprietary data. One of the nice things about starting a company in 2017 is that there are tons of great resources available to you. Free or cheap services that solve what used to be really hard problems are readily available. One such service is Foursquare. When we launched Winnie, if you opened the app in an area where we didn't have data, instead of showing you nothing we instead showed you results from Foursquare. This was admittedly not the best experience, but it gave people affordance to still find places and write reviews.
Refusing to go market-by-market also forced us to build a bunch of proprietary and very cool infrastructure that collects data at scale. One early system we built could actually figure out which restaurants had changing tables and highchairs, nationally and instantaneously, at a VERY low cost. I can't say how we did that but you'd be surprised at what's possible if you have the will and ambition :)