Weird ads

Today, for the first time, I've had 3 weird ads from a California address.
One advertising combat glasses?
Two show the same photo of a woman reclining on what looks like a bed (it's a dim room and photo is b&w) and the blurb is inviting you to tick a box to see the reason why she has multiple ...you know what.
I contacted eSet security who monitor my mobile as, although I could 'unsubscribe', I had never subscribed in the first place.
ESet thankfully blocked both sources but I was wondering how they got my email address. I have two.
One (the one in question) is my main email used only for anything to do with finances/banking, family and my utilities and I have ticked 'no marketing' from all of them.
The other is for online shopping, friends and anything else.
Have you dealt with similar issues?
Who knows who sells our info, all in the name of keeping us 'updated' and 'quality' control.