PC world reckons the Box account will always be free [1], and Hojoki says that there will always be a free plan [2].

[1] http://www.pcworld.com/article/2018603/get-a-free-25gb-box-a... [2] http://hojoki.com/#plans

It doesn't really sound too good to be true to me. A file hosting service is able to buy large hard drives and then commoditize their space. A dollar currently buys about 20GB. So if one of these 25GB users decides to upgrade, then each month, they will pay the overhead for 10 new 25GB users (forever minus the cost of occasionally replacing old hard drives, bandwidth, etc.), or 40 new ordinary free 5GB users.

Moreover, if somebody uses even 10GB, they're pretty well locked in to box.com. That's more than any competitor I know of gives with free accounts, so to switch, you'd be looking at paying, right off the bat, for service you haven't vetted yet.

So while 25GB may feel generous, it's really only a one dollar loss leader, and the "catch" is built in to ordinary usage of the service.

Box.net runs this type of promotion regularly. I remember, I got 50GB free lifetime (till company survives) account by signing up using their iPad app.

I got 50GB for signing up with my android a while back, and I haven't seen a bill yet.