Isn't this the same trick that some newspapers and magazines have been using for ages? Show the title and the first paragraph or two, hide the rest of the article behind a paywall.

On the surface, the most noticeable difference is that this uses BTC instead of USD. But since the example amount (0.0005 BTC) is approx. $0.22, which is well within the range of a PayPal micropayment, there's little reason why it can't use USD instead.

So the real innovation here is not the choice of currency, but rather that you're using micropayments. If done right, this can eliminates the friction of purchasing a subscription. Since $0.22 is literally pocket change, you might even be able to make people pay a lot without knowing it. All those quarters and dimes can add up to a sizable sum.

Realistically, however, it will be too much hassle for readers to shell out money every time, and too much hassle for publishers to manage all those micropayments. So there might be a valid business model for a middleman that lets people keep money in a prepaid account and spend it little by little with participating publishers. You could even automatically deduct a small amount each time someone opens an article and keeps it open for X seconds. At the end of each month, each publisher receives a lump sum that is much easier for them to manage. You, the middleman, deduct a fee for providing the API and some neat statistics.