During June, Auto Trader saw 63 per cent of its traffic coming from mobile devices.

Of the 44.3m visits the site received during the month, 43 per cent (10.3m) came from smartphones, and 20 per cent (8.7m) from tablets. While tablets share of traffic has remained fairly static in every month of the year so far – after a post-Christmas jump of two percentage points – smartphones share has been creeping up month-on-month, from 39 per cent in January.

The vast majority of tablet traffic (85 per cent) came from iPad – and 17 per cent of those users also downloaded the Auto Trader iPad app.

“The fact that mobile and tablet use has exceeded desktop should come as no surprise,” said Auto Trader market research director Nick King. “What is more interesting is the rate of change and the fact that car buyers seem to be blazing a trail in the use of mobile devices. Nearly seven in every 10 full-page advertisement views were made on tablet or mobile last month. That should be a rallying cry for dealers who question the value of optimising their websites for mobile devices.”

Auto Trader saw searches for cars on mobile devices exceeding desktop back in March 2013, nearly two years earlier than Googles forecast date for the web at large, 4 December 2014.