Why isn't there a law that nobody can sell or trade your personal information without your consent? When my name and address are being sold to a nebulous charity - at least give me a cut of the action for dealing with the mountain of junk mail that is to follow! Seriously though...

Everytime I donate money to a charity, apply for a card, etc, I change the spelling of my first name slightly. Then I know from which source the unrelated mail comes from, then I write 'opt out' letters.

Much better if we had an 'opt in' system, whereby your info remained with just the entities you choose.

My postmaster told me that without junk mail the US Postal Service would not survive.

Or you can do what I do... ask that your name does not get put on a list. Tell them up front that if they do not honor your request, they will never see another dime from you. Works like a charm!

I never get junk mail... opted out of everything, even mass mailings.

Just me, but I think that's what all these special cards at the grocery stores, drug stores, etc., are all about.
I once emailed one store and asked why they needed that and they said so they could notification of special sales, coupons, etc., to their customers. When I asked where my were because after several years, I had gotten nothing, they didn't answer - still have gotten nothing.

I think they not only sell the information as to name, address, phone, etc, they sell other information. A store receipt can tell if you have pets, if you buy alcohol, if you smoke, any condition you might have that requires over the counter medication, etc. It's probably worth quite a bit to them.
A drug store receipt could even show what ailments you have for which you are taking prescription drugs.

You know even if you pay cash at some stores, they always ask for your phone number. I always tell them no - my daughter just makes one up.

Unfortunately that law we need will never get passed. Something about lobbyists...

As consumers get more and more savvy on how info is shared and how products are force fed to us, most of those marketing tricks start to fail - the day will come that people will only fall for a sales pitch the first time and then punish the company for hounding them by never buying from that company again. I have a long list of companies I refuse to do business with and whenever I get the chance to bad mouth them I do it. It usually shuts them up.