Online retail has reached a “tipping point” as new research suggests all online retail growth is coming from sales through mobile devices.

According to IMRG and Capgemini’s e-Retail Sales Index, sales thorugh desktop websites flatlined in the second quarter of this year, while 23% of all online retail sales in the period came through smartphones and tablets.

It is the first time the index has been able to strip out mobile data from overall retail sales.

The index says the sales show a “significant change” in consumer behaviour as shoppers migrate from laptop computers to mobile devices, as they search for accessibility and convenience and they gain increasing confidence in m-commerce.

The strength of mobile retail is high causing the index to reforecast annual growth up to 15% from the 12% prediction made at the beginning of the year.

IMRG chief information officer Tina Spooner said: “Online retail is a sector that sometimes receives a strong boost from supporting technology and mobile is certainly providing that at the moment. The latest findings, together with the continuing trend of triple-digit growth in mobile commerce, provide clear evidence of a culture change in digital shopping.”

The index revealed that while tablet devices account for 85% of mobile sales in the year to date, sales through smartphones have grown faster, rocketing 210% against 130% for tablets in the second quarter.

Moss Bros ecommerce director Neil Sansom said: “The days of just optimising full-version sites are over and retailers are now going to have to find new levels of skill to optimise mobile as part of the customer journey. Tracking journeys across multiple devices and giving customers relevant content will be a new exciting challenge for ecommerce and it is sure to be the next frontier for retailers to embrace.”