The goal of any public pressure tactic is to force an organization to change its policy. Not to deny it revenue. If you're not doing the former, then all you're accomplishing with the latter is making yourself feel good about 'doing something'.

And how do you force it to change its policy simply by not buying its products? Why would a company, particularly a worldwide conglomerate, care whether you buy their products or not?

Hint: You've already said it.