That's a good point, but if it was limited to just Netflix's own content (depending on how they own/license their own content), it shouldn't be too much additional cost, right? Basically the cost of the bandwidth, but maybe lower the stream quality on their channel.
Yeah, if they had royalty free content. Though most of what's in their catalog doesn't really qualify as "play in the background" sort of stuff which was what was being discussed upthread.
The general concept would probably be interesting for a lot of people if the numbers worked.