Not liking to have one is kind of tough, it is almost always necessary in order to get credit.
And the point I was trying to make. If O2 don't require you to have one (a data only SIM carries little risk compared to a full data/calls/text SIM), they may get more signups.
Every one I saw in my local Apple store was getting connected to O2 - so that may be why?
I doubt it, a friend of mine couldn't get an iPhone for ages since he was certain O2 wouldn't give him a contract. Of course now they're on other networks he can.
Given their sometimes dubious levels of customer service, especially when it comes to Apple products I think people are staying away from there.
Can you not remember the story where a laptop bag handle snapped and they refused to replace it as it was being used to carry a Macbook pro? they claimed it wasn't Mac compatible as they're too heavy compared to other laptops.