Getting fans from the grassroots
As a solo hobby artist who does more studio work than live work, I constantly struggle to get new listeners to hear my music. The obvious hope is that by exposing as many people as possible to my songs, a few of them might purchase something, and a few of THOSE people might recommend me to someone else. Building that promotional web is hugely important in exponentially increasing the reach of your music.
Artist Josh Rosenthal explains his own take on this, and other grassroots marketing techniques in action, in a podcast he recently did with CD Baby.