In this weak, unfocused Slate article that’s kind of about bailing out the publishing industry or the future of publishing or something, there is a fascinating nugget:

In the mid-1980s, before he founded Slate, Michael Kinsley came up with an ingenious scheme to …  stimulate the purchase of books and verify that buyers actually read them. Kinsley went into bookstores around Washington and inserted coupons redeemable for $5 in the back pages of trendy political best sellers. No readers ever claimed the prize, which he took as proof that people in Washington buy books to say they did rather than to read them.