The 16GB iPhone 4S comes with 750 minutes, unlimited texts, 500MB of data, and insurance. It can be had for £55, approximately $85 US, a month with no upfront costs. The 32GB phone is available as well, although it will set you back a little bit more each month.
While the year end cost is pretty close to purchasing a device and paying for a regular plan on O2, business, and perhaps some individuals, may find it more appealing to be able to upgrade their handsets yearly and have the piece of mind that comes with the insurance that is included in this offering.
source: The Register