Today Netflix releases the third series of “House of Cards”, a political thriller starring Kevin Spacey as Frank Underwood, a double-dealing politician. “House of Cards”, which began as an American remake of a British mini-series (in turn based on a novel), is the prime example of the online-video company’s strategy of making high-quality, television-like content with which to woo subscribers away from conventional TV and differentiate itself from rival streaming services. The plan is working critically as well as commercially: “House of Cards” has picked up Emmys and Golden Globes, making it the first online-only series to win American TV’s highest accolades. At the end of last year Netflix counted 38m streaming subscribers in America and 17m abroad. As ambitious as Underwood, it is hungry for more, expanding country by country. Next month it launches in Australia. That’s how you devour a whale: one bite at a time.