I'm not sure I understand BMW's slogan on that page.
"Graduate to a car that puts you in the driver's seat."
Is it suggesting I've been letting someone else drive this whole time? Maybe. I mean, these are college grads, so BMW might be saying, "Hey, you're on your own now kiddo. Time to ditch Mom's SUV and get behind the wheel." But that's a bit of a presumption, right? I mean, most people attending college are over 16, so wouldn't the vast majority of those willing to get a car already have one? Or suggesting the concept of "ownership." After all, won't a lot of grads still be driving the hand-me-down sedan Dad traded up from, or the reliable Junker bought with the cash from the penny jar just to get them out of high school? Most won't really feel like that is "their" car, so maybe they're suggesting that by being the one who signs up for this car, I'm really "in the driver's seat" now. No more familial obligations. Just me and the road! Also, how is the BMW itself going to put me in the driver's seat? Physically. Yikes! That's scary.
And... "graduate?" As in "complete a course of training?" Jesus, you mean I need to do a TEST to get this car? How pretentious. I'm paying you. Give me the car. Or, wait, maybe they're using "graduate" to convey the sense of "changing gradually along a scale" with the suggestion being along an upwards path. If this is so, that's presume a bit. What makes the BMW a graduation from my current vehicle/means of travel? You're assuming a lot BMW! You should be selling me on this BMW, not insulting my choice of motorized locomotion.
Ok ok, joking aside, as has been said, it's classic, standard incentive. There's an incentive for every occasion, if it'll get you to sign. I guarantee you I could find a company or dealer willing to knock $1,000 off MSRP if I told them it was my birthday... provided I agree to sign that 10 year lease to celebrate.