When it comes to marketing - getting something appealing in front of eyes is what you need to worry about. Just putting it up and hoping it hits the top 5 isn't going to do it. You have to pimp that thing out everywhere.
This is very easy to see in Kickstarter campaigns. The ones that succeed are not necessarily the ones with the nicest looking videos or projects. I've seen some very good projects, with good production in their promo, fail because they did not get advertised enough.
The same goes for those super-talented magicians who just can't seem to find many gigs. ADVERTISE!
Make no mistake - if you want to make ANY money selling a product you have only two options. Sheer, dumb luck and hard, hard work. Guess which one has the better chance of turning out well? If your product is something you believe in, and want to sell, then you have to push it to sell it. Make people realize it's something they must have in their life. The more eyes you get the idea in front of, the more people will buy.