You're a self-published author with (I presume) no history, celebrity status, connections, or money to promote your novel.
There are so many things working against you.
Given the current state of the self-published market, your odds of making any kind of money from your (presumed) starting position are essentially equal to your chances of winning the lottery. Even a truly glorious cover isn't likely to help much.
Well, that's a cheery outlook. I'm not saying the cover is going to sell the book like crazy. But if one cover sells 5% more books than another cover, than it's worth testing. For example, 50 Shades of Grey has nothing but a necktie on the cover, whereas other romance novels have characters in sexy poses. There must be some data on performance for the various types of artwork. And regarding first time writers and how we all suck and could never expect to earn a penny, how about Margaret Atwood, L. Frank Baum, William Blake, Ken Blanchard, Robert Bly, Elizabeth Barrett Browning, Lord Byron, Willa Cather, Pat Conroy, Stephen Crane, e.e. cummings, W.E.B. DuBois, Alexander Dumas, T.S. Eliot, Lawrence Ferlinghetti, Benjamin Franklin, Zane Grey, Thomas Hardy, E. Lynn Harris, Nathaniel Hawthorne, Ernest Hemingway, Robinson Jeffers, Spencer Johnson, Stephen King, Rudyard Kipling, Louis L'Amour, D.H. Lawrence, Rod McKuen, Marlo Morgan, John Muir, Anais Nin, Thomas Paine, Tom Peters, Edgar Allen Poe, Alexander Pope, Beatrix Potter, Ezra Pound, Marcel Proust, Irma Rombauer, Carl Sandburg, Robert Service, George Bernard Shaw, Percy Bysshe Shelley, Upton Sinclair, Gertrude Stein, William Strunk, Alfred Lord Tennyson, Henry David Thoreau, Leo Tolstoi, Mark Twain, Walt Whitman, and Virginia Woolf. And here's some ebook success stories for you:
http://www.huffingtonpost.com/ronald-h-balson/bestseller-success-storie_b_4064574.html