That'd be my guess too. One of my never executed pet projects was a service that aggregated all of the streaming providers libraries and let me quickly filter between genre, provider and "magic" looking for something I'd wanna watch. Most of the other services don't seem to have netflix level APIs, so it would have taken some trickery to get something approaching a comprehensive catalog for them...

I built http://streamjoy.tv as an abstraction layer above netflix, itunes and amazon and I will attest it took quite some trickery to get something approaching a comprehensive catalog. Even things that should have been simple like using the main python library for Amazon's product api was not simple because I had to rewrite sections of the library that dealt with api throttling limits.

There are gaps in the APIs and though they can be dealt with, it was not always easy or straightforward.

Good site, I use it all the time. Poster child for why Netflix doesn't like APIs very much, though: there's a giant Hulu banner ad front and center!

Yep, it does. Amazing site too.