If you don't have at least a few public domain items in your stable of products, you are missing out on an excellent opportunity to increase your residual income.  If you've never heard of the public domain, a simple explanation of it is books, music, photos, etc. that are free for public use due to expired copyrights, invalid copyrights, or they were created with taxpayer money. 

If you know where to find these items, you can take them, repackage them, and turn them into your own products and services to sell to others.  Find 5 or ten public domain books, use them as the basis for your own products, and set up a website for each of them that consists of a one-page sales letter and a way to pay you for the item, and you're in business. 

I stumbled across an excellent source of public domain books this morning - it's a private site run by a long-time entrepeneur and his intellectual property attorney.  They find public domain works, screen them for any legal problems to make sure you have clear rights to use the items, then put them into both .pdf and Microsoft Word format for you to download.  You get 5 of these public domain works every single month - all ready for you to use as your own. 

This is one of the best public domain resources I have come across, so make sure to take advantage of this information today!