I fucking opt out already.
I buy stuff for my lab. I get email. I don’t care if your widgets are on sale — if we don’t need one, I won’t be buying any. I don’t make any “OMG, those 100 microfarad capacitors are to die for” impulse purchases for the lab. (well, not many) I don’t like the companies that spam me like this. You don’t get partial credit for letting me opt out after I’ve been slimed.
This goes for cold-calling, too. I’m an adult, who managed not to kill, maim or noticeably disfigure himself getting a degree in experimental atomic physics. I’m capable of ordering a new set of of whatchamacallits when I need them. Sometimes even before, so we have them on the shelf! So no, I don’t have any product needs you can fill today. Buh-bye.