Possible Clues:

• Report of where you'll find tiptop wines in popular book
• No. 1 hit novel (2 words)
• Book bought in large numbers
• What's good for the writer is very good for the wine, by the sound of it
• It takes the very good salesman to dispose of so much involume (4.6)
• By the sound of it, you can't do better than get your wine from here in volume
• Sounds as if the wine is excellent here, and popular in volume
• The champion salesman may be judged by volume, perhaps
• The sort of volume that comes in considerable volume
• Sounds as if the finest wines may be had there in volume