Apparently O2 UK has received three and a half times more subscribers during Q3 of 08 as in Q3 of 07; currently O2 UK has in excess of 19 million subscribers and thus is the largest in the UK.
The reason is obvious though…the Apple iPhone 3G along with simple tariffs have contributed to the success and more than likely will continue to prove successful as long as O2 carry the Apple iPhone.
Times do change and the economy has taken a dive down for the worse, so it will be somewhat interesting to see just how O2 UK does fair in future.
Source — zdnet