Tracy, Try putting something like this on each of your products.

The original purchaser of this document is granted permission to copy for teaching purposes only. If you are NOT the original purchaser, please download the item from my store before making any copies. Redistributing, editing, selling, or posting this item or any part thereof on the Internet are strictly prohibited without first gaining permission from the author. Violations are subject to the penalties of the Digital millennium Copyright Act. Please contact me if you wish to be granted special permission.

I saw your store on the home page of Teachers Pay Teachers; so, I thought I would look at your freebie. I have a couple of suggestions that might help you to better market this product. First, create a cover page which can then be used as an attractive thumbnail to entice buyers. Also add a second page which is a directions or suggestions page. List several ways you use this product in your classroom. Never assume that a buyer knows how, why, or when to use your product. Finally, put the copyright symbol in front of your name so people will know it is your product. Other sites have been known to download the free items from TPT and then try to sell them. I hope these suggestions help.

I am now your 2nd follower, and hope you will reciprocate at my store as well. http://www.teacherspayteachers.com/Store/SciPi/Products

Good luck as you sell on TPT!