The popularity of long running television shows provides a good argument for sustained entertainment, but not really for lengthy entertainment. Episodes really aren't that long, and while watching entire seasons in one sitting seems to be gaining popularity with
Serial shows definitely exist (and are awesome) but they don't usually net the kind of results that network executives are looking for. I think the most common form of television is a sort of combination of the two formats, where the particular episode stands alone, but there is an overarching plot that can provide a higher level quality to dedicated watchers.
Long movies still exist, many video games take quite a while to beat, and people still read (thankfully), but the Internet culture has a significantly short attention span. I say that, but there are people that dedicate their lives and put in a copious amount of hours into online games.
I want to say that I have hope because of the great fan bases that develop around certain serialized shows, but I'm not sure that it should really be called hope, or that I should have hope in that at all. There's got to be some way to use the knowledge of what people like to my advantage. Maybe I'll look into formatting my novel into a series of short stories. That's always been an idea, but it's sort of a terrifying one seeing how little people care about short stories.
I would say that short stories are where it's at, but short stories seem to be a dying art. You people don't pay any mind to them unless they've got pictures to go with them. Short stories in a vacum are under appreciated, but short stories mixed with other mediums seem to be viable.
I don't know. I need to get writing.
TL;DR TL;DRs are where it's at.