The Grateful Dead, many other "jam bands", and other musical groups, have found that freely giving away some of your material HUGELY increases your fan base. Ever since the Grateful Dead started allowing tapers to bring equipment including mic stands, and tape and distribute live shows on a non-monetary basis, their popularity zoomed, they were established as icons of the culture, and they even achieved MTV playlist status with "Touch of Grey".
This model works well for them because
- they have other sources of income in their work/art, such as concerts and commercial releases.
- they continue to perform new material & new variations, which new and old fans then seek
- they have a unique style, which is best heard, and even better heard from concert/live recording vs studio
- fans trading their music, and giving to new fans, is "viral marketing", before the term was coined
Some reasons then why one might want a different model
- "greedy" for every last penny (perhaps justifiably so)
- unable/unwilling to keep working and producing great output
- product, while perhaps original and unique initially, remains fixed, or becomes stale or repititious
Now I am not really going to make the moral judgement of how long someone should be able to copyright their works, and hold them in their own tight control. I would believe that old works should be public domain at some point, and also that creativity deserves some reward.
However, there ARE points in between in which both the artists and the public can benefit overall, and as the Grateful Dead and other artists have seen, giving to your public does not always mean taking away from yourself as the artist. Fair use can help an artist, and the public domain help cement artist in history, but "permitted use" by an artist speaks directly to their strongest fan base and evangelists of their work. Even Stephen King has given away book chapters online, on the premise that you will buy the rest. He may not have gotten much richer, but I'm sure he reached fans.
Or if you prefer, you can wait in front of a book store in the mall to sign your books, and hope to explode into fame.