This is a Promo that I stumbled on today, and have no idea how long it will last, so hurry to take advantage of this genuine, "no strings attached" offer. I've successfully registered and got my storage space.
Link: https://app.box.com/signup/o/hp_business
"Activate your 50GB Box account offered on all new HP Business Elite and Pro series PCs and tablets". Please do not be concerned about the HP requirement, as I have a non-HP machine, and it worked absolutely fine. This is what you get: 1 User; 50 GB of web storage; 250 MB file size limit; Secure transfer and storage; Simple sharing and collaboration; Mobile app access