It's also not uncommon for companies to outsource e-mail marketing to third parties,who may turn out to be spammers, or who outsource to spammers themselves.
Kelloggs made that mistake, but when I pointed out that I hadn't signed up for "My Special K" e-mails, they cleaned up their lists and I haven't had a single spam from them since.
Saga, on the other hand, did not. They actually admitted to using the services of a well-known spammer-for-hire, and that they had "listwashed" me with said spammer-for-hire - which has since resulted in even more spam for pensions, equity release and funeral plans. Not to mention even more spam from Saga !
An organisation that can't treat me with respect right now is NOT going to benefit from me in old age or death, that's for sure.