There is a line.Can they really be classified as bad marketing ideas when you remember them and what the product is for?
While we may think they are stupid/annoying they get you talking about them which is therefore the point.
Ultimately you need to drive sales. And while remembering it is a big part of that, if people remember you extremely negatively then you probably wont drive sales so the marketing would be a failure.
If you, for example, put up a billboard that said "**** you, des moines' with your product logo.. you probably would be remembered, but you probably would lose a lot of sales.