The public domain is full of books, journals, literary works, videos, audio, music sheets, software and government works that you can use any way you choose and create unlimited wealth with a little creativity.
Several ways you can profit using public domain works are:
1. Creating articles to increase website traffic.
Search for public domain works that are related to your business and dissect these works into informative little articles you can post to article based websites others can freely use as content in their ezines.
At bottom of each article include your signature file which briefly explains more about your business including your contact information.
The length of each article is up to you but it should offer useful information related to your business.
2. Republish public domain information
Find a book in public domain and create a course around it. You could offer an email course, audio course, teleseminar, or a CD-ROM of music, sounds and even clipart or photo collections.
One man sells US Military vehicle pictures on eBay and offers collection on CD-ROM. He generates a few hundred dollars a week from just this one collection.
Imagine how many other collections you could easily put together in a weekend and sell them on eBay.