This here is the juice: Big data. The more customers they have, the better - they have validated full names, birthdates, addresses and CC numbers (and most likely also ethnicity) linked with the data when they visited what movie and even if the customers repeatedly visited a movie.
MoviePass has, effectively, four distinct customers:
a) the moviegoers themselves, where MoviePass makes a profit on everyone watching less than 1 movie a month
b) the vast amount of adtech/big data/consumer analytics companies for which this data is a goldmine
c) the movie studios which can (as shown in the article) use MoviePass to promote movies
d) the cinemas which profit off the customers wanting to eat and drink
They have, of course, monetized a) and begun to discover how to monetize c) - it will be interesting if they find a way to monetize the data.