I'm guessing this CLA will have better luck in the USA than the BMW 318ti and Mercedes Coupe. For one, it's a sedan. Two, it's a pretty decent size (about the same size as a C-Class). It most likely will cut into C-Class sales, but that's Mercedes' problem, not consumers' problem.
And I actually like Mercedes and BMW's business model in Europe; selling many different models at many different price points. Maybe because I'm an auto enthusiast and I don't let brand image fog my judgement, but I really wouldn't care if my landscaper pulled up in a BMW or Mercedes. It wouldn't prevent me from purchasing one. That's just me.