There are lots of people selling the promo codes that Tracfone sends out to people for free!. This is such a scam.

FYI: Don't anybody pay some guy $2.99 for codes.
Here you will find all the codes free for anyone who could use them:

http://tracfone-codes.com

You use the promotional code when you redeem an airtime card and it adds a certain amount of extra minutes free