Back in '06, I joined a service that was, at the time, called GreenDimes. It's now called "Precycle," and is one service of a web-portal company called Tonic. It's basically a service that triest to reduce junkmail coming to your home. (I sort of wish they would get back to just focusing on, and expanding, their original service, since I frankly don't care about the rest of what they're doing. But I guess they were having trouble making money on that; the direct marketers have been lobbying state legislatures to try to make it difficult for companies like Tonic to act on behalf of consumers -- they want laws that say a third party can't opt out for you, you have to do it yourself. Anyways, it seems like they've stopped investing effort in adding more catalog-mailers to their database of "companies whose catalogs we know how to stop".)
In any case, when they originally started, they offered, as one of the options, a long-term membership, and all memberships were based on periods of time. They've recently changed the policy to basing membership on location -- you buy once for your house, but you have to re-register when you move.
I wrote in to complain about the fact that this basically meant they wouldn't be honoring my long-term membership. Within minutes, they emailed back, and after a few quick exchanges, we agreed that they'd refund most of my original membership fee. They actually offered to refund the whole thing, but I would've felt guilty about that, so I said they could keep the equivalent of what it would've cost under the new policy to register at the places I've lived while using their service.