NotebookLM has been one of the more useful projects I've used. Being able to focus a language processing model directly to the content you're looking for is really useful.

I currently support a data application where the vendor's documentation for it is not particularly well organized. It's spread across dozens of PDFs, sometimes without particularly well reasoned organization. Dumping all those PDFs into NotebookLM has been extremely useful since it allows us to ask questions that either give us answers, or are immediately fruitless requiring us to contact the vendor. Having an LLM capable of processing all that text has been great.

I've also used it with tabletop roleplaying game manuals. It's especially useful for badly organized TTRPGs, or those with poor indexing. Being able to type a question out in the middle of a game and getting an answer without having to dig through the book and find it yourself can be really very useful.

What I've never found a use for is anything in the Studio pane. They're neat tools, but... it's never been anything I've wanted or needed.

Ha this is one of my uses as well! I'm running an FFG SWRPG campaign and being able to ask it questions about overarching connections between plotlines helps quite a bit.

The mind map feature is also handy, although last I used it, it was a bit clunky to export.

Interesting about the TTRPG. I am a fan of 3D6 Down the Line, the (criminally Under-watched) Actual Play series..where they were doing Arden Vul, a massively intricate mega dungeon..I bet it could have been useful to the DM to look up info over plain search