Amazon Go

What I do not understand is: Why do they need to know that it was me who got something off the shelf? They need to know when something has left the shelf, so they can refuel, and they need to know when something leaves the store, so they can charge.

But do they really need to know when you pull out an item and then give up buying it?

It's kind of the only way to do it without having an RFID tag on everything which would be expensive because they'd have to either special order the items from the manufacturer or apply them themselves both of which are costly. That's one of the major sticking points that has prevented this from showing up in normal grocery stores for years.

I read a bit more about, it seems that following the whole process, not just check in and check out, it becomes harder to steal an item.

"Because it works by watching actual items come off the shelves — instead of reading a tag or RFID chip, for example — you won’t be able to steal items by removing or altering tags."