Measuring Success

As I've begun a self-publishing experiment, and started slowly to make connection on Twitter and Facebook and the like, I've been amazed at how many people are out there trying to do the same thing. The internet gives writers and other artists a great platform for delivering their material to an audience, but the sheer volume of sites and artists and other diversions makes "success" in conventional terms a tough thing to realize. As I've watched the sales numbers climb on Amazon and B&N (7 copies sold--impressive, huh?) I've asked myself what kind of success I need to feel satisfied. Is it enough to have my book finished and out there for people to read (friends and family so far)? Can I be satisfied with that? If not, then what is the magic number? A thousand readers? Ten thousand? A million? More? Artists want an audience, there is no denying that. But what is the measure of success?