Phones4U JUMP scheme offers 6 month

Phones4U reckons it has reinvented the mobile phone contract with its new offering, JUMP, which promises phone upgrades every six months.The acronym stands for 'just upgrade my phone' (see what they did there) and sees you taking out not one but two contracts – one with whatever network you're using, which covers your airtime and data and all that, and one with Phones4U that covers the hardware side of things. You even pay two separate direct debits.This double contract has to be taken out for a minimum of 24 months, but over the course of that time you can change your handset every six months, if that's what you a) want and b) pay for To upgrade your phone so regularly requires you to pay an extra £2.99 - £3.99 (average) per month.You do still have to pay for the new handset though: either by trading in up to three old phones you just happen to have knocking about, or by splitting the payments across the remaining life of your contract.Ready for the overly complicated maths? Okay, here goes.If John goes to a Phones4U store to take out a standard contract for a non-iPhone handset on a £35 per month tariff, he'll now get the option to take out the 'JUMP' option and pay £37.99 a month instead.That's £15 of network time with Orange and £22.99 service agreement with Phones4U.John walks out with, say, a Samsung Galaxy S2 and a warm feeling in his heart.After 6 months, John might say, "Sorry Samsung, this phone's very nice and all but it's just not an iPhone. Gotta get me one of those iPhone 4Ses that I've been hearing so much about. How else will I know if I need to take an umbrella out with me each day?"Now, John can either trade in his S2 for £175 (Phones4U's example, might not be accurate), which is taken off the remaining payments he has to make on the 'JUMP' contract.So that's £413.82 of JUMP minus £175 of phone contract, leaving the JUMP portion of his bill at £9.95 per month for the remaining 18 months.But the monthly cost of that magical iDevice is £28.49, which you then have to add to your £9.95 contract hangover PLUS the £15 network bill for Orange. So you've upgraded to another snazzy new phone, John, but your monthly bill is now the significantly higher £58.44.And you want to do it all again in another six months? We've got to say, it doesn't look like the cheapest (or easiest) option for someone who might want an iPhone in six months' time – SIM-only might be the way to go there.But then again...But hey, what do we know? "We conducted extensive research prior to the trial and national roll-out to inform the JUMP model and ensure it truly met consumer needs", said Phones4U's director of customer development, Alistair Firth."We want to give our customers the freedom to own the very latest smartphones like the iPhone 4S without having to wait 18-24 months for an upgrade. The idea for JUMP was born out of research we conducted that revealed people were frustrated by the inability to upgrade their handsets sooner."We used these findings to help shape the JUMP offering and believe it offers the best flexibility and benefits of any deal currently available on the market."So when Phones4U says jump, you say never mind that, where's my new phone?