Just changed broadband providers due to movig house and O2 have been superb. If you have an O2 contract or pay-as-you-go sim (as long as you top up with £10 once every 3 months on the pay-as-you-go) then you will be eligible for the saving. They have other higher specification packages that also include the discount. I have been an O2 mobile customer for years and have never had a problem. All other broadband providers seem to cost £10+ for the same service. Seems to be a good deal
They have won countless awards for their service (check link below)http://broadband.o2.co.uk/home/awards.jsp?cm_sp=Broadband-_-HomeBroadband-_-Awards
Subject to availability, BT line, direct debit and min term contract. Customer Service calls are free from UK landlines and O2 mobiles. Discounted price quoted is for O2 Mobile customers. One discount per customer and per connection. Discount for Pay & Go customers subject to £10 minimum top-up every 3 months. Fair usage policy applies.