Tents

I've gotten a lot of spam in my days, but today I got the most funny introduction of an unsolicited email ever:

"Dear Sirs,
It's my great pleasure to contact you !
We learned from Internet you are interested in tents. We have been in this line of business for many years. We wish to establish friendly business relations with you and share the mutual benefits."

TENTS?
Where on the internet did they find out about my secret desire?