Big Brother

So, I'm one of many people who have many email accounts.  I created one a few years ago when I got a new iPhone for work to create an iTunes account that was separate from my home account.  This was after I'd left my old life.

In my old life, I was a member of CostCo.  Where I was geographically there was no CostCo - Sam's Club was the local warehouse store.  I was no longer a member of CostCo, but at some point I started getting CostCo e-mails at the new account which I was reserving, I admit, for mostly commercial e-mail kind of stuff.

I really didn't think twice about it.  Until they told me my annual renewal was coming up.  I scratched my head wondering, but, again, didn't think much of it.  Thought they were mistaken.  Whatever.

Now I've been in Canada almost two months.  And this is an account I only access on my iPhone.  I may have logged in once or twice on the computer, but it isn't an account where I am particularly active.

So imagine my shock - still in quite a bit of disbelief - when a little over a week ago, CostCo sent me an email from Costco.ca.  The Turbo Tax ad had a maple leaf and all.

WTF?

How did they know I'm in Canada to customize / change the emails they are sending me?  At what point did they realize I'm here for longer than just a vacation?  I mean really?

And since then, there have been three more e-mails from them.

Makes me wonder what communicates with what around here.  Did Gmail communicate to them where I was when I opened (or frankly, just likely deleted immediately) their prior emails?

Anyone with any plausible explanations would be useful.