I agree with the above posts that don't think 25p is too much to pay to be told that you don't need to spend £5 an hour waiting for a flight that's delayed. But I guess if you don't fly or wait for people at Heathrow then it will probably be cheaper !!

This service will pay for itself over and over if you just once avoid unneccessary and completely unreasonable parking charges.

The other real benefit of this service to me (as a passenger) is getting messages while abroad, telling me (hopefully ) that my flights on time. I don't usually have access to the Internet when away, other than through my phone.