Most authors do their own self-advertising. Only the creme-de-la-creme get major backing for their books, and sometimes only after they've made it big. C'est la vie.
An easy way to advertise yourself, especially in a forum like this, is to make good use of your sig line. It's the perfect advertising place, but right now yours is dominated by a series of letters and plus marks that make no sense to outside readers.
Instead, try posting direct links to where potential readers can buy your books. Use a thumbnail of the cover. Do the same on all the forums you visit that allow customizable sigs. It's free and it saves you the trouble of awkwardly trying to bring up the topic of your book in conversation.
As a side note, I wouldn't make your primary site deviant art. Trying to advertise and sell your written work from a free art site seems counter intuitive to me. I saw that link and thought it meant you drew fanart, which is not the impression you want people to have (and if it's not your primary site, I have no way of knowing because that's the only link in your sig.
) Try a blog if you can't get your own domain, but you should think seriously about moving away from deviant art.
And like Tbora said, get someone to review your work. It'll do one of two things - give you a review that will entice people to read it, or show you where you need serious improvement before people will be willing to buy it. Agents like Nathan Bradsford have weekly sessions where you can submit a page or two and have it critiqued. There's also Query Shark. Even if you don't plan on submitting to an agent, you can get your query worked by the Shark and learn how to write a really compelling summary - something that should also help with sales.
But above all,
keep writing. Don't stop just because you have an ebook out. The more you write, the better you'll get and the more chances you'll have that people will buy your work.
