I really hate these type of offers where you have to register and buy online to receive any of the savings.
There is just so much that can be missed within the small print if not read very carefully.
I prefer "and advise" people to, Stop, Think, make a list of questions that you would like answers to.
Then telephone the company concerened and ask your questions.
If you are then happy with the answers to your questions, then by all means go ahead and sign-up online.
Questions:
1. What is the penalty for early cancellation?
2. ?