Is the free laptop deal a good one from carphone warehouse?

I am in the process of buying a laptop but i will also have to sign up for broadband so this seems to be saving me money (as it all seems expensive at the moment). however as i know there is no such thing as a free lunch i was wondering what the catches are??
Answer
Two year contact of £20 a month which is no bad considering you get a free laptop, it is a dell but rubbish spec, ask them if you can pay a bit extra and extra some better spec. i have not done this yet but looks promising,