[gnicholas]

According to others, it does not invent the items — these are submitted by users.

Seems like they could run a CourseHero-style business model, where you get access for X months in return for uploading Y creations. Some people would submit junk, but you would get enough good stuff that it would be worth it. Also, you could make the default value for submissions low, but give big bonuses for submissions that reach a certain level of popularity.