Currently the trial is limited to 5 users and something like 100MB of file storage. I was actually more worried offering a free-tier
would result in people abusing the service (i.e., using it to store/share illegal stuff).
However, just between you, me, and the internet, I actually haven't enabled the logic to lock trial accounts out at 30 days. Because I'm still unsure about it.
I'm personally not a fan of time limited trials -- I think feature or usage limits are better, especially when you don't have any users yet, and you need people to use the app and give feedback...