Here's a ~5 minute talk with 5 such examples (where relatively simple ML models made a 1M+ impact at a FAANG) :) https://youtu.be/zyOEOd1HkSY?t=946
Happy to talk about more details if you message me through my profile!
Interesting examples, and yes, they're all the kind of thing that might not justify the effort for an ML model (and might not have enough data to train) for a small website or operation, but can easily justify the cost and effort when you have a huge number of transactions.
On another note, this is why I often like lightening talks. So many people think that what they're doing falls below the threshold for what is an interesting presentation, when in fact it's the most relevant thing a lot of people will see at a conference.