Are Dota 2 Keys still being sent out?

Does anyone know if Valve is still sending out Dota 2 invites? I've been hoping to get one and have filled out their survey, but I haven't had any luck so far, and occupying my friends account for 5 hours a day to play Dota 2 isn't a very good gesture, so I was wondering if keys are still being sent out and if there are any other ways to get the keys besides the survey? Thanks!