£4bn - that's how much crappy mobile sites are costing UK retail

Poor conversion rates depriving retailers of as much as 12 per cent of potential revenues.

New research from website optimisation technology specialist QuBit says poorly designed web sites (or sites that aren't mobilised at all) are combining to ruin the mobile shopping experience of many consumers.

It found the conversion rate on mobile is vastly lower than on PC and tablet because of eight key areas – speed, ease of conversion, navigation, local, ‘thumb friendliness’, seamlessness, visibility and mobile redirects. 

The study said iPad users on retail websites generate 25 per cent more page views than a desktop user and those that go on to purchase will have a 22 per cent greater order value. 

In terms of conversion rates the desktop is still best, with tablets converting 13 per cent less, while mobile users convert 80 per cent less frequently than desktop.

The need to provide a better experience on mobile is all the more pressing because of the sheer volume of traffic coming to retail sites from handheld devices – up from five per cent in 2010 to 15 per cent now.