Over here in the UK one of the cinema chains (Cineworld) has a thing called an Unlimited Card. For £14.99 a month you can see as many movies as you like (with a couple of restrictions). Given that single adult ticket prices are now over £8 for 2D films it's pretty easy to see that this is a no-brainer if you want to see more than a couple of movies a month. Having one also tends to expand your options of what movies you see in the cinema - for example, back when I was paying full price for movie tickets, I'd only have gone to see triple-A blockbusters every once in a while, but now I go to the cinema most weekends and usually see two or three movies including some that aren't on the A-list.
The restrictions aren't particularly onerous: you can't book online or by telephone, you have to show up at the cinema with your card (it has a photo on it, so it's not transferable); once you've got a ticket for one movie you can't get another movie ticket until after the first movie ends; and there is a small surcharge for 3D movies (currently £1.50, and you need to bring your own 3D glasses, or you can purchase some for a further 80p). I was initially a bit concerned about not being able to book in advance but I've had the card for almost 2 years now and the only time I ever had any trouble getting in to the showing I wanted was Harry Potter 7 part 2 (I was able to get in to a later showing).