Just had (another) weird coincidence happen.
Quick backstory:
A few days ago I was troubleshooting (what I thought) was a defective porch light (replaced an old fixture with a new one - which wouldn't light up once installed). Further investigating led me to realize that the light switch itself had an intermittent fault in it as well.
Anyways, during a subsequent (landline) phone conversation with my sister (my android phone was nearby, within earshot), I relayed this story to her, including having to replace the light switch.
Shortly afterwards I started seeing Home Depot ads on my Facebook feed for...Lutron light switches (exactly like the one I replaced). I NEVER searched for or looked them up anywhere during my troubleshooting - all I did was walk out to the garage and grab one that I already had on hand.
This isn't the first time something like this has happened.
I can't recall all of the details, but a few years ago I was at a gathering of friends, and one of them mentioned some obscure product, which then started showing up in sidebar ads on websites I visited shortly afterwards.
And one last one:
Also a few years ago I was in Monterey, near Cannery Row (by Gump's restaurant), when I pulled up Google maps (to look around the area for what other restaurants were nearby).
Since I had the phone out, I decided to check some email as well - and in the junk mail folder (NOT Gmail, but a non-Gmail email account) was a freshly delivered email from...Gump's.
Either a very strange coincidence, or my phone tied my other email account to my Google identity, and conveyed that to whatever algorithm sends out ads (apparently in real-time, as I was literally standing in front of Gump's when it arrived).
Anyways, that is all. I'm convinced that smartphones are constantly listening in, and acting on what they hear.