As general consensus goes, a BComm(Management) is virtually useless compared to a Business or quantitative major. This is because the course isn't really teaching you to be a manager, you can only get that from having experience actually managing people. A BComm(Marketing) is less useless than a Management degree, but when you compare it to a major in Actuarial, Finance, Accounting etc., it does have a lower job outlook. This is not to deter you however, if you truly love Marketing and want to get into a marketing role (Mad Men what what!) this course would be good for you. However, if you want to have a stronger, employable degree (possibly in a field you won't like as much), then a different degree might be better.
Remember, if this is your dream course, please enrol in it. You'll only regret it if you don't.