It looks like a cheap way to start using the internet. For £10 you can test it and see if it suits your needs. The rate works out at just under 0.5p a minute. I used to pay OneTel 1p a minute plus 3p each time I connected. It worked out at about £20 a month for very limited access. Now I pay £17.49 a month for NTL Home broadband, which is approximately five times faster than a dial-up connection, and I have unlimited access.
Try it and see what it is like. If you find that you spend more than £10 a month, start looking for alternatives.