True, but unless Im mistaken there is an online only subscription, the sole purpose of which is admission past the Paywall. If nothing else, every dime generated from that is related to Times decision to sell an online product.
Additionally, in print media, subscriber revenue surpassing advertiser revenue is huge and not something that would be likely to happen without a successful digital product for a couple reasons.
Beyond that, yes, there's nothing here but correlation. However I think there is enough in the first two paragraphs to make a case.
As a former publishing professional, no - there isn't. If the article were to differentiate between online subscription revenue and print subscription revenue, and were to control for other factors that ALSO drive switch to subscription, then you could make the case that the paywall is "working."
