The rush for books at Barnes Fair

It was a beautiful day for Barnes Fair. I always visit the book tent, which seemed busier than ever this year. I got chatting to the lady who sold me some, and she said they had taken £5000. And that was before noon. Ebooks, Amazon and other alternatives don't seem to have made much impression here. Or are people just buying books on the cheap because they fear they won't be so easily available in future?