@Iluviaporos - The problem with that is that when you are applying for that job as a car salesman, you are going to be up against three other candidates with business or marketing degrees, because so many people get degrees these days.
It's got to the point where it's not just a matter of making more money. In a lot of positions, you simply can't break in anymore without a degree.
Which is actually ridiculous, because a lot of these positions don't require a degree of any kind. It's just that, when your resume crosses someone's desk and there are a pile of others in front of it, you have to be competitive. So if they've all got degrees, you have to make sure you do as well.
I wouldn't be surprised if the learning effect was stronger than ever, even though it's got more to do with initially getting the job, in my opinion, than in excelling in it.