HCOD, eBook User Bill of Rights and Math | SarahGlassmeyer(dot)com: "SUMMARY: U.S. Libraries circulate about 2 billion items per year. This means each person that has a library card averages about 13 checkouts a year. Given that the average price of a book is about $20 (low estimate), that means the value of materials circulated by libraries is 45 Billion dollars or $270 to each borrower.
If each borrower changed one checkout to purchase – $3,750,063,240
If each borrower bought one eBook at $6.00 – Publishers would get $1,001,352,000."