I think TV series are bigger than films now. They have established characters and story line spanned over several shorter episodes with cliffhangers and recaps etc. Once you get into a series you follow it for several seasons. It's a preferred way to tell stories.

I usually prefer films over TV series because I find just these tropes tiring. I find TV series have quite inefficient story telling and spend most of its time trying to get me hooked to watch the next episode.