From the back of the box:
"An enterprising goblin has set up shop in Baldrick’s Tomb! He’s ready to sell you top-quality adventuring gear for reasonable rates (for being in a dungeon, anyway). And that’s not all! Open For Business introduces floor cards, floor-wide effects that are drawn when you first enter a floor.
"Throw in new monsters, traps, scrolls, and treasure, and you can see why the goblin was so eager to set up shop!"
Open for Business is an expansion for Baldrick's Tomb, which adds two new decks--wares and floors--and offers many new cards to the existing decks in the base game. Additionally, the treasure cards included in this expansion double as tools; you can hang onto the for gold at the end of the game, or discard them for powerful, one-time-use abilities!