It definitely lets artists network with other artists, as well as other industry people, which can be really helpful for upcoming artists. Artists can learn on what is happening in the music industry and because this site has both artists and listeners, they can get constructive feedback on how to improve themselves. Its also a means of building awareness, but it shouldn't be the only way. An artist should use many different channels to themselves known. Basically, I don't think its a total waste of time, but like greedygreg209 said only 10-15% of artists make a profit, so I think an artists has to utilize every channel of exposure as they can. Here is an exerpt from a 40-page essay that I wrote for one of my classes on the music industry which shows how almost impossible it is for an artist to be successful:
"Over the last five years, there was an average of approximately 36,000 new releases per year (RIAA “New Releases Figures”). Last year, 31,704 new releases were introduced to the market (a five-year low), but only 6,455 were released by major labels (Tindle). Of these 31,704 new realeases, 72% sold less than 1,000 units. In addition, on average, less than 10% of new releases will make a profit (RIAA “The Cost of a CD”). Furthermore, only 61 of these releases sold in excess of 1,000,000 units, but these 61 accounted for 38% of total new release sales (Tindle). New releases represented 294.8 million (56%) of the 526 million total unit sales in the U.S."