Just want to add my two cents about the perceived advantages of attending top schools vs lower ranked schools...
My boyfriend is a columbia grad in a senior position at a top consulting firm. We have this discussion all the time, especially with me applying to business school. He's interviewed harvard grads that have been unemployed for a whole year post graduation (actively looking.) At the same time, certain firms are very selective as to where they recruit, which is the reason I myself don't want to go to just ANY school. With that said, FOR ME, number one isn't necessary, but a school with a sound program that employers will not doubt is.
As far as those stats, they really are just a number- from an unspecified data pool. I've heard numerous stories about unemployed mba grads from top schools, or employed grads making mediocre salaries (less than my sister who has a BA in psych and works in pharma- and is about 7 years younger than the people I hear about.)