They say they help us save money. This is where I the found page and posts relating to Tracfone bonus codes. That page is also bookmarked in this Diigo group.
There's a description on here of how you can validate the bonus codes you find. Also, they tell you a way to do try the bonus codes on the Website instead of adding airtime from your phone. The post says that you can try a second code if the first doesn't work. And so forth, even though there is perhaps a limit to how many tries you can make.