I will surely disclose more in the next future, granted.
About what's real, I think that it's mostly the need. I read every tweet that comes on the "iubenda" search, and frequently look to the profile of the user behind. Most of the times the user is a web designer, which proves that people subscribe because they feel the need. Moreover, I interview almost every beta tester that we invite, and again I get people really passionate about the product.
I think that the marketing-driven risk is mitigated by the fact that the product is explained very well on the website, and people signup only if in need of the product.
It would be nice if iubenda does something similar a few months after they exit private beta to show us what numbers are real and what is just success theater.