That's when online shoppers hit problems with a website and become so frustrated, they turn off the computer and turn back to the high street.

It's been identified by web testing firm SciVisum, which says web rage has affected 78% of online shoppers.

Although more than half of customers said they shopped online because it was fast, less than half would forgive even their favourite e-tailer if they suffered problems more than twice.

SciVisum's Deri Jones said:

"Web rage is a burgeoning online phenomenon. With less than half of online shoppers prepared to give their favourite website more than two chances to get it right, the message to e-tailers is very clear.

"Online shoppers are showing zero tolerance to poor performance - and e-tailers must follow this lead if they're to avoid losing their customers to competitors or the high street."