How Often is too Often?

I receive a lot of e-mail. Most of them are off mailing lists from organisations that I like to keep up to date with. Some like to send something out every week to keep me up to date. But some like to absolutely saturate my inbox. Do they think that I’m a millionaire? Of course, the easy way out is to unsubscribe. But they’ve already thought of that. There’s an option to send me less e-mails. So I click the button to make it happen, and I now get their stuff three times a week instead of five. I don’t know whether it’s taken effect or is it because the weekend that I unsubscribed was a bank holiday and it didn’t count? Maybe if I buy something it steers them away from marketing more products because they know that I’ve visited their site. But I’ll still receive an e-mail from them telling me what I’ve bought. Either way, it’s insane to keep thinking that I want their custom every week.