I would say that opt-in could see some success if used in place of paywalls, etc. Sure, not many people are going to opt-in to "please give me some money, I wo

I would say that opt-in could see some success if used in place of paywalls, etc. Sure, not many people are going to opt-in to "please give me some money, I work hard", but if the New York Times said, this article is for subscribers, but you can read it if you'll mine for me while doing so.