kharris:
Neither of those services are free... and HBO requires geo-unblocking (as does Netflix if you want access to a decent catalogue).
You are right. We primarily subscribe to SVOD services for access to TV shows. Having movies to choose from is an added bonus. The alternative for us is paying to hire one from the iTunes store, which is why we consider them a source of "free" movies.
I also understand HBO can be a bit tricky to geo-unblock for some, but we've never had any issues.
On that note, we've had limited success with geo-unblocking Netflix, so have generally been using their NZ catalogue. There's still some movies of interest there.