I've bought domains through Godaddy, and can therefore vouch that it's one of those temporary promos which they do offer every once in awhile. They're not promising that the price will now be $6.95 forever, after all. It also might only apply to this week, so buy while the buying's good. I've never had any problem with them.
As to why the discount doesn't show up right away, that's mentioned in their price promo banner: "Your discount will be applied in your shopping cart." Meaning that after you're done picking out which names you wanted and you go to the checkout to pay for them, the promo dicount will then be shown there.
So happy hunting!