Advertising is the Capitalist Religion equivalent of the prayer pulpit. It's a means of social control which exhorts worshippers to acts of holy consumption, and also defines the moral basis of society - conspicuous and competitive egotistical materialism.

You can't take advertising out of the picture without pulling down everything around it. Removing it won't make everything better on its own, because there are so many other elements - work culture, resource exploitation, human exploitation, corporate sociopathy - acting in concert with it.

The best you can hope for is an attempt to claim some media space of your own for alternative values and goals. 'Buy media' would certainly help, but it would help more to have a clear social goal which isn't just about Jobs™ or any of the other standard cliches.