Are they active, recurring users? I bet a good number of those are people who tried it for a week or two, realized it didn't cover their needs or they couldn't keep up with it or they didn't like all their information siloed in one application or something, and then stopped using it.

Like I tried Evernote once, for example, and I'm probably counted in that list of users, but I never used it for more than a couple of days before going back to Google Keep and Google Docs (with some Scrivener when I want to make an ebook).

It's easy to get tons of users if you're selling $10 dollar bills for $1 dollar.

Vast majority of whom have never paid a dime for an Evernote product.

User isn't the same as customer, though. Evernote needs customers. They only have users.