Unsolicited e-mail

No, not the Nigerian scam sort but the sort that comes from a business once it has your e-mail address.
It is understandable that they should add you to their e-mail database but it is irritating and, I think, impolite. It is even more irritating to have to give a reason before they will unsubscribe you. (I wonder if it will even work and whether, despite claims to the contrary, they have passed the address on.)
I am not a person easily swayed by advertising. I use the grocery advertisements to find out which of the two supermarkets has likely items on special but that is about it. I am happy to visit bookshops and secondhand bookshops and that is about it. I do not enjoy other shopping. Perhaps it has something to do with a certain lack of finances but I suspect that even with finances shopping for other items would not be particularly interesting. I wonder how the Japanese can make a national hobby out of shopping. They have limited space so they must shop for small items - and where do they put them?