Construct a financial model to identify the revenue$-$maximizing approach for The New York Times$$

digital product $--$ no paywall, a $$leaky$$ paywall, or a $$bulletproof$$ paywall $--$ on both sources of the

company$$s revenue:

$1.$ Advertising. When paying to reach their potential customers, Advertisers consider both $$Reach$$

$($the ability to put their ads in front of a large number of potential customers$)$; and $$Frequency$$

$($the ability to show a potential customer their ad multiple times$).$

A$.$ Unique Visitors. Assume $20\%$ of advertising revenue is driven by the unique visitors

metric provided in the case, which is roughly the number of different people who read

content