How can an online dating service get my email information if I have not been online looking?

I have been receiving mail from dating services, they have my email address, and I don't know how they are getting it. I have not visited any dating sites, the only thing has been filling out surveys, and job searches.

How can an online dating service get my email information if I have not been online looking?
You need to send an email to the dating site and ask them to remove you.
Reply:Another group who's site you entered (or gave your email to) could have sold the information to the agency.