So, for example*, if you can take out a subscription to the Financial Times online in about 30 seconds online, by clicking on a few options, then you should be able to cancel your subscription by clicking on something on your subscription details on their site. And they should not require you to email their support desk, reply with a second email explaining why you don't want it any more, and then answer a phone call wherein they offer it to you cheaper and then have to insist that, no, really, you don't want it any more.
The rule shall, instead, be that if ten random people take longer to unsubscribe than they did to subscribe that your home page will be replaced by a big flashing sign reading "We will treat you badly in the hope of holding on to your money."
Secondary rule: No introductory offers. Free trials are allowed (but must be easily cancellable, as above), but you can't offer new people a better deal than your existing customers. Introductory offers are a way of tricking people into signing up, and then hanging onto them when inertia stops them from cancelling/moving. Instead you must offer a good deal in the first place, which is sustainable, and which is easily compared to your competitors. I know this makes life harder for companies who are trying to hide long-term costs from their customers. I really, really, don't care.
*Or, possibly, exactly what happened to me at lunchtime.
Original post on Dreamwidth - there are comments there.