it's easier to do a search for marketing tips - because i know there are many threads about it already. you'll want to watch your aberrations, i'm pretty sure it will print despite that, but i'm not a 100% certain of it. any art can sell, and i can see a few sellers in there. but the fringing takes it down a notch. the edges are a bit oversharp as well, they stair step in places.
you'll want to add more keywords, and a bio that doesn't sound like your fresh out of school. increase the price of the card, people buy them as small prints.
marketing - you'll have to find the people that would be interested in your art. that's the hard part.
---Mike Savad