I get hundreds of e-mails per day on my junk gmail account. One thing you could consider is using modifiers on your new junk account. For example if your e-mail address is junk@gmail.com, you can enter comps with junk+wildearth@gmail.com (or junk+whatever_the_company is) as the sign-up e-mail. I wish I had done this from the start. Then you can just automatically filter out (or delete) some mailing lists automatically. It's good for telling which companies have security leaks or sell your details.
Going to have to sign up for a new email address for comps.. started entering them recently and my spam went through the roof.