Free Gifts allows you as Store Owner to give for free products for a timeframe to bust your sales.

When your customer buy something, they will be notified about the free product when purchasing more then $X.XX amount, doing so, makes your customer buy more to get that as a free product.

Features: http://customscriptz.com/wiki/Free_Gifts#Features
System Requeriments: http://customscriptz.com/wiki/Free_Gifts#System_Requeriments
Screenshots: http://customscriptz.com/wiki/Free_Gifts#Screenshots

Note: This module has been tested and works fine with no moded version of Zen Cart v1.3.8a and above. Older versions might work, but if not, you will have to upgrade your installation.