'In May, I wrote up something weird I spotted on Google's account management page. I noticed that Google uses Gmail to store a list of everything you've purchased, if you used Gmail or your Gmail address in any part of the transaction. If you have a confirmation for a prescription you picked up at a pharmacy that went into your Gmail account, Google logs it. If you have a receipt from Macy's, Google keeps it. If you bought food for delivery and the receipt went to your Gmail, Google stores that, too. You get the idea, and you can see your own purchase history by going to Google's Purchases page.

Google says it does this so you can use Google Assistant to track packages or reorder things, even if that's not an option for some purchases that aren't mailed or wouldn't be reordered, like something you bought at a store. At the time of my original story, Google said users can delete everything by tapping into a purchase and removing the Gmail. It seemed to work if you did this for each purchase, one by one. This isn't easy -- for years worth of purchases, this would take hours or even days of time. So, since Google doesn't let you bulk-delete this purchases list, I decided to delete everything in my Gmail inbox. That meant removing every last message I've sent or received since I opened my Gmail account more than a decade ago. Despite Google's assurances, it didn't work.'

-- source: https://tech.slashdot.org/story/19/07/05/1728200

Cheers, Peter