It also doesn't mean that I consented to receiving marketing emails when I overlooked a checkbox at the bottom of your order/checkout page when I purchased something. Ethical companies will make this an opt-in choice, not opt-out.

Agreed; this is gross. If I've signed up for an account on someone's site, all I'm implicitly consenting to are transactional emails related to the service (or product, if there is one). Things like shipping notifications and billing reminders and such.

And if you at least have a checkbox for consent for marketing emails during signup, it should be unchecked by default. I'm so tired of this crap.