The proportion of online sales made through mobile devices doubled in the three months to the end of July.

Mobile accounted for 23.2% of online sales in the quarter, up from 11.6% in the second quarter of 2012, according to the IMRG Capgemini e-Retail Sales Index.

The proportion of online retail site visits made through mobile devices also surged, from 21.1% in the second quarter last year to 34% in the second quarter this year.

Over the last three years the mobile penetration of online sales has grown by more than 2,000%, with the penetration of online retail visits via mobile devices growing by 1,100%.

However, the research found that the switch in device types “appears to have had a knock-on effect for bounce rates”, which increased from 21.7% in 2010 to 27% in 2012.

In the quarter, click and collect represented 16% of online sales – a record high. This compared with 12% in the equivalent period last year.

IMRG chief information officer Tina Spooner said: “There appears to be a correlation between the surge in mobile commerce over the past 3 years and the rise in visitor bounce rates on e-retail websites.  While consumers have generally become more confident in using their mobile devices as a shopping tool, the latest data suggests they have also become more demanding.

“Higher search volumes will inevitably result in an increase in bounce rates as shoppers will often compare products and pricing across several brands. However, by offering an engaging and relevant experience for customers across all channels retailers will ultimately achieve the end goal of higher conversion rates and an increase in customer loyalty.”

Capgemini UK vice-president of consumer products and retail Chris Webster said: “The record high levels of online sales via mobile devices corresponds with record high rates for click and collect. This correlation of mobile ordering and location flexible collection is at the heart of the mobile internet and the impact it will have on consumer behaviour. Maybe we are truly entering the Martini age - anytime, anyplace, anywhere”.