Honestly - if it were my airline - I probably wouldn't. It doesn't increase value all that much; so many folks have access to streaming media now, and if we're offering plenty of bandwidth anyway ... why bother?

For those who don't have a device, or don't want to use their own, the series of movies and shows onboard is plenty.

Why bother getting into the live-content-distribution business if you don't have to? The negotiations on that sort of thing can be very painful. Not to mention all of the complaints - such as "why can't I watch Milwaukee's ABC? This one's from LA!" or what-have-you. No good deed goes unpunished.