Starting this week, prime time FOX network shows like So You Think You Can Dance and Bob's Burgers will be available to stream live on FOX's website and on the FOX Now app for the first time ever. The catch? The service is for pay TV subscribers only.Despite the paywall, FOX's decision is a pretty big deal. FOX had previously only made their prime time shows available on demand after airing, presumably so streaming defectors didn't impact FOX's live ratings. Even early FOX appearances in skinny bundle services like Sling TV featured FOX On Demand rather than a live FOX stream (for OTT services like Sling TV, the live stream issue was further complicated by the fact that FOX has different local programming in different markets).But now FOX appears to be embracing the streaming model, though this latest expansion of live streaming is limited to subscribers of pay TV services. It's an interesting place to draw the line, considering that FOX is already available for free over the air in many markets. Over-the-air FOX fans won't be thrilled with the paywall, but this is still an important step for a major network to take.