The skill set is the same, just used differently.
Film school won't hurt your ability to make commercials, but if you're looking to learn more about the marketing needs of such productions, I don't know what to tell you.
I majored in Advertising and minored in Marketing, so I feel you on the commercial thing...As I understand it, if it's not a one-stop shop that does everything, then the ad firm writes the commercial, then gets the director. There's not much autonomy...the client and the firm are on set, and can override just about everything.
I'd almost think you'd be better off getting an MBA with a focus on Marketing, and then taking some basic production classes at a New School/Extension type institution...because while most programs might not make you focus solely on feature films, I can't think of any program that will accept you making commercials for every single assignment.
Another avenue might be to produce spec ads and put 'em up on the web, then apply to full service ad agencies or try to freelance. I love web content and marketing, so sometimes I like to do parodies as well as thinking about series that tie in a brand...so many of them are doing it now...
Good luck...