Possible Clues:

• Something bound to prove profitable?
• It's hot
• Popular book in French is small, digested by beauty, 21
• Successful book rep doing more business than the rest?
• Literary chart-topper
• Top salesman, hardly needed to shift this?
• Standout work
• Birdsong, perhaps, in worst dungeon, by the sound of it?
• #1 on a list, maybe
• Footballer George with, it’s said, store of wine that’s market success