Sales per reader who buys products (a) …………
Contribution margin ratio (b) ……………………….
Contribution margin per buyer (a) × (b) ………..
$48
$40
Number of readers buying products (a)………….
910
1,000
Contribution margin per buyer (b) ………………..
$48
$40
Contribution margin provided by ad (a) × (b) ….
$43,680
$40,000
Differentiation value ………………………………….