I do the same but regularly get spam. I just got a spam email today for automobile insurance and the source was an automotive buying company I used about a month ago. The businesses don't appear to be related in any way.

The strangest one ever was an email address given to a boutique spa hotel in Oregon showing up on spam announcing a new production from a local California community musical theatre. I must have given the hotel my zipcode as well so the email was sold based upon my location.