I agree that the page is a bit poor in communicating why you should pay, and cumbersome to use. OTOH, the paypal order page does indicate how much money you put towards each of the goals, so I suppose it is possible they abide with the UK laws.
Personally I would be happy to have a monthly subscription to simply keep Ubuntu improving, even without any additional value on top of what they already provide. I realize this could be done by simply donating monthly. However, in a subscription model they could probably set up a two-way communication channel between them and paying customers, to both help refine their goals and estimate how well they're being met, in a more continuous manner than random donations at download time.
Personally I would be happy to have a monthly subscription to simply keep Ubuntu improving, even without any additional value on top of what they already provide. I realize this could be done by simply donating monthly. However, in a subscription model they could probably set up a two-way communication channel between them and paying customers, to both help refine their goals and estimate how well they're being met, in a more continuous manner than random donations at download time.