How could this have happened?

This is a story from a while back that always baffled me -

I was doing some passive reading on a man called Rudolf Steiner. It was an academic site with no affiliate or commercial incentive of any sort (at least nothing apparent).

Not even a week later, I was mailed at my actual postal address, addressed specifically to me, a catalogue from a health and beauty company that I'd never even heard of before.

So I open the first page to see a homage to this Rudolf Steiner, who's principles, incidentally, inspired the company's naturopathic products.

I'm right in assuming this is more than coincidence I get this catalogue addressed to me, right?

I mean as a guy, and one with virtually no real interest in nail creams and such, I did no browsing on the subject - only on the man in question and on what appeared to be an academically inclined site.

Heck, lets say my memory is a little hazy and I did inadvertently click on a link somewhere to a shop selling this stuff - or get re-directed.... How the heck do you get an address from an ISP IP???

“Your mind is working at its best when you're being paranoid.
You explore every avenue and possibility of your situation
at high speed with total clarity.”
― Banksy, Banging Your Head Against a Brick Wall