I think almost all the companies have a X days money back guaranty
Sign up now, give my credit card, and to cancel I have to call a phone number which may or may not work and talk to a person who's entire reason for employment is to make it difficult for me to cancel with no assurance that anything has actually been cancelled until the next billing cycle.
When I take over the world, it will be a law on pain of summary execution that any recurring billing which can be signed up for online must be cancellable online :/