What has been your strangest ad targeting, and what’s the most likely logical explanation (if any)?
A day later, I was browsing Facebook on my home desktop and saw an ad for the exact same item in my feed.
It's likely they partner with data brokers of credit card companies for your purchase history. For me, this is the only explanation, as I did not talk about the item out loud, and have no mic-enabled Facebook-owned app on my phone in any case. As a low-tech solution, correlating IP addresses with "suspected companion device" is also likely.
My only explanation is that I searched for several far future dates for pricing on airbnb in my condo complex. airbnb knows my email, knows I searched my own home thus indicating I’m a potential lister. Airbnb sells/leases this information to manorshare who then used my email on Facebook for direct targeting.