Joel,
Many casinos are running BJ Tournaments and giving Promo Chips as prizes. This is the trend over the last 5-10 years of BJ, or any other table game tournament.
There are 2 kinds of Promo Chips: the ones that are one-timers (win or lose, they take the Promo Chip). The kind you mentioned in the D BJ Tourney are what we call "real" promo chips. Yes you have to play them in the Casino (and they are usually in denominations of $100 or $500), but they are worth 100% of what the face amount is. The others are worth, at best 50%, if you can find a bet on which the house has no advantage.
BTW- Good Luck; and, if you happen to win some at the D, call me at 772-349-9194 and I will tell you the best way to play them off.
Peter Nathan
I have played in over 400 major BJ Tournaments.