‘Stay with the publisher’ shows that you make $12 for every book sold. ‘Sell through the Web site’ is a bit more involved in that it shows that you first must cover your fixed cost before making any profit. Note that they intersect at about 9,100 books sold, which means that you would be indifferent to which business model you chose at this volume of books But at less than the 9,100 you should stay with your publisher; at greater than that volume, build your own Web site.