Spoke to Sprint a couple days ago about this and was told...... You must call Sprint for the feature to be activated for $1 a day, and you call to deactivate it when done. Any overages will be prorated. So basically if you need it for work/school on Tues and Wed you call to start it on Tues and call when your done on Wed to have it turned off, costing you $2 a week.
Still cheaper than a hotspot devise. Interestingly enough the sales person (at a franchise dealer) also said as she walked away, "you can also jailbreak the hotspot feature" "we know how to, but I can't talk about that"