The Marketplace Expansion is three add-on decks in one, along with some new Patrons and Dirty Deeds. 
 
The Market deck gives you more control over what you have on offer in your Tavern. 
 
The Reputation deck helps you earn Renown to have more choice over your new clientele each round, and the Events deck adds fun unique effects and abilities affecting every Tavern with a new event each round.