I used to see people create open source scripts/softwares and give out for free to the community and rely on donations to make few bucks out of it. Not really a good source of income but wouldn’t hurt if you do something as a hobby and people donate you some cash when they use it. But relying on donations may not fetch you as much as it would if you sell your script for a buck or two.
The way I see it, open source hobbyists are becoming smarter in business models and instead of giving the product for free, they are charging 99 cents to 5 bucks. A silly Magento CAPTCHA module I came across sells at $4.99 and most of the scripts from the vendor are of the same price. The vendor also has a community forum for people to help each other if they fall short of handling support tickets. With this kind of business model you (vendors or freelancers) are sure to make good profit. iPhone Apps are another good example of how people are being tempted to own an app for just 99 cents. Considering millions of downloads of each app, you will be quick to make a million.
My advice to freelancers building products in free time, sell your product for a buck or two rather than put it free.
About myView: myViews are totally my point of view of things I see in the industry. Could be a good analysis or just stupidity.