Unfortunately, it is an experiment that doesn't end. It gains strength and runs amok. Just about everything explodes, and companies sprout like mushrooms. Now we get careless and start doing things without caring about others' feelings. Or their pocketbooks.
Money is no object.
We acquire and spend and try everything under the sun. We think we'll be young forever. We stop going to sleep at normal bedtimes, and we play outside our sandboxes. Email marketing just gains steam and is accepted as a solid way to communicate with customers, as long as companies play by the rules. Opt-in is one of those rules.