[pants2]

I've never in my life seen a useful product tour. They're always blatantly obvious like "THIS IS THE SEARCH BAR. USE IT TO FIND CONTENT ACROSS OUR PRODUCTS AND SERVICES."

The best UX is using obvious and standard design, plus a searchable menu / command palette.

[c0balt]

Ime, the only useful product tours where in games, I. E., tutorials. This usually extends up to in-game hints at certain features like a characters ability. A lot of software can probably pull inspiration from there in regards to including hints with minimal interruption during usage (tooltips that are shown longer the first time you use something etc).