This is either a case of freaky timing, or someone is watching over my shoulder and it's tinfoil hat time :)
I just bought some bike lights from Torpedo 7 (paid via NFC linked card on my phone) ... just drove back to work, opened Slashdot on my laptop and right there in front of me is an advert for bike lights.
I've done no Googling for lights on my laptop or at home, I just walked in and impulse bought them.
Anyone know if Google Pay data is used to do targeted adverts ?