There’s been even more talk than usual lately among cartoonists about "free" content, and I think this recent post, "Why Are You Giving Away Content For Free?" over at Dosh Dosh explains it better than most.
The truth is, if you want to sell more products or services, you need to develop a reputation which exceeds your slogan, sales letter or promised benefit. Free content is a tool which helps you to develop publicity. It will eventually generate demand for services, products and premium content.