If the short qualifies based on our content policies, then the company would be fine to add. The question is really just whether the film qualifies. Budget doesn't really have much to do with it, it's really about whether it's had an official release (theatrical, film festival, etc...)

TLDR; there's no rules for companies, if the content they make qualifies to be added to TMDb, then create the company.

Oh. I pretty much thought the main thing to look for first is whether or not something is professional, and if something is professional it belongs in the db. And I thought one of the main things to look at, to decide if something is professional, is if its produced by a professional company.

It's still all very confusing to me. Why might Blood Alley may or may not be allowed on the db?

It was apparently released only on the Internet. I don't see any theatrical or film festival release, do you? If not, then I don't think it qualifies. (It's also a bit unusual that they used the same title as a well-known 1955 film starring John Wayne & Lauren Bacall, directed by William Wellman. Seems a bit dodgy to me.)

I guess I still don't really understand what does and doesn't belong. I thought maybe it would be accepted on the basis that it's made by a "professional" production company (and I don't really know how to judge that either).

EDIT: If something is professionally made, then that means it don't need a theatrical or film festival release, right? That comes from the amatuer content guidelines, no?

Content allowed in the Movie section:

...Movies released directly on video

Movies released via a professional digital platform...

Does low-budget production company = not a professional production company?

Terms like low budget (usually used for professional content), independent film and production company are often misused by amateur filmmakers. There is usually no legally registered film production company and movies made at home (school, ... wherever!) obliviously have little to no budget.

It was apparently released only on the Internet. I don't see any theatrical or film festival release, do you? If not, then I don't think it qualifies.

I agree. I checked Lincoln Kupchak's earlier work too and it looks like all his films were self-released on the web (YouTube, Vimeo, Amazon). The only screenings mentioned are 48 Hour film festival thingies, the Chicago Horror Film Festival and a university showcase. The director is a professional visual effects editor who works for Flash Film Works but, at a quick glance, he do not seems to have any professional experience as a filmmaker.

If something is professionally made, then that means it don't need a theatrical or film festival release, right? That comes from the amatuer content guidelines, no?

Yes. Film and television series made by established production companies are fine as long as they are (or will be) released publicly.