The Free Edition has a much simpler user interface and only support sniping one auction at a time. Because its simplicity and free of charge, it is ideal for casual eBay buyers who usually don't snipe multiple items during the same time. Click here for more Free vs Pro feature comparison.
The most obvious reason of releasing the Free Edition is to promote the Pro Edition and www.joybidder.com web site. However, I have another reason of my own.
Most of my registered users are savvy eBay buyers and some of them are eBay sellers who makes a living by buying/selling on eBay. They understand how a good auction search/tracking/sniping software can save their time and money. Since they make money on eBay, the small amount of registration fee is never their concern. In fact, lots of my users have told me that I have priced JoyBidder way too cheap. But for casual eBay buyer who buy from eBay occasionally and only snipe one item at time, they will very unlikely use many advanced features or buy the software. The more advanced features I added to JoyBidder, the more I tailor to savvy eBay users and the further I alienate from the casual users. There has to be a simpler product for those casual users.
Compare to Pro Edition, this is much simpler, isn't it?