Since both iTunes and Amazon are internet marketplaces, it makes sense that most of your movie sales will come via the internet. And as a result, you will need to make sure people actually know your movie exists.
If you’re like most filmmakers, you have a website for your movie. And odds are good you are trying to fit too much into it. So the first thing you need to do is remove all the distracting crap. Whenever I mention this at a talk, invariably someone asks me how to determine what’s distracting? It depends on your website objective.