IT costs are booked to the project or if you are lucky to central licensing bucket which can aggregate users and obtain a discount. Either way that comes out of my project bucket which is already besieged by too many expenses.
If you have a current process, an incremental improvement to it might be a hard sell at $500/mo. And I can guarantee that at 1k users, the $15k/mo is going to be a far harder sell than 'use sharepoint/the public file share/e-mail, it works fine'.
Dropbox already proved this point.
Think of it this way.
If you've got 30 people, you're using this product. Then you add another person.
Now all of a sudden you've got 500$/month expenditures suddenly appearing. The sudden appearance is much more likely to push people to alternative routes than a gradual increase.
I'm saying that someone is much more likely to look around for alternatives to do something if an expanse suddenly pops up than if an expense gradually does.
This is most likely going to discourage startups and other small-but-growing companies from using AeroFS.