I noticed you did an article on ads in books.
Ironically, I am currently holding an eBay auction for that very purpose. My auction made Adweek Magazine! You can read about it here: https://www.theopenpress.com/index.php?a=press&id=2328.
The Adweek article is here: https://news.yahoo.com/news?tmpl=story&u=/adweek/20050620/ad_bpiaw/shoptalkonechapteratatime.
You can see my auction here: https://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5592706975.
Just wanted to let you know that some authors are effectively doing this! Thanks for your great article!
Michael T. Owens