The $39.99/mo plan is the same price as the prepaid $479.88. Aside from the obvious, paying everything up front, what's the incentive of the prepaid if both plans still lock you into a year-long contract?
with the prepaid, you don't have to remember to make payment and you don't have to check that your cc is under it's max and therefore, you don't have to worry about your subscription being cancelled and you being assigned a penalty for early termination.
So essentially the monthly is mostly to Adobe's advantage. So that they have an opportunity to gouge you if you slip up. Gotcha!
For people like me who remember to pay their bills on time every month, there is no incentive to prepay. It's essentially the same plan, not a discounted price. Usually, the incentive is a slightly discounted price if you pay upfront. I also don't see the point in locking someone down with a contract for the month by month option for the entire CC suite. It defeats the purpose of month by month for customers. There is no absolutely no incentive here! Adobe?
the incentive is a lower cost for the annual plans (and both plans you cited are annual plans) and there's no malevolence in offering two ways to pay: not everyone can afford the lump sum payment.
there are also monthly plans paid monthly so if you only need adobe programs for 2 months, you only pay for 1 or a few months and there's no obligation to continue longer than the paid-for month(s).
the annual plans are the same as leasing property or a car. you make a commitment for a certain time-period and breaking that lease incurs a penalty.
i think about ~month 7 it becomes less expensive to purchase the annual plan and pay the penalty rather than subscribe to a monthly plan for ~7 months and incur no penalty.
There is a 50% cancellation fee on the remainder of your One Year Contract