An online entrepreneur says that poor spelling is costing the UK millions of pounds in lost revenue for internet businesses.
Charles Duncombe says an analysis of website figures shows a single spelling mistake can cut online sales in half.
Mr Duncombe says when recruiting staff he has been "shocked at the poor quality of written English".
Sales figures suggest misspellings put off consumers who could have concerns about a website's credibility, he says.
The concerns were echoed by the Confederation of British Industry (CBI), whose head of education and skills warned that too many employers were having to invest in remedial literacy lessons for their staff.
Mr Duncombe, who runs travel, mobile phones and clothing websites, says that poor spelling is a serious problem for the online economy.
"Often these cutting-edge companies depend upon old-fashioned skills," says Mr Duncombe.
And he says that the struggle to recruit enough staff who can spell means that this sector of the economy is not as efficient as it might be.
Figures from the Office for National Statistics published last month showed internet sales in the UK running at £527m per week.
"I know that industry bemoaning the education system is nothing new but it is becoming more and more of a problem with more companies going online.
"This is because when you sell or communicate on the internet, 99% of the time it is done by the written word."
Mr Duncombe says that it is possible to identify the specific impact of a spelling mistake on sales.
He says he measured the revenue per visitor to the tightsplease.co.uk website and found that the revenue was twice as high after an error was corrected.
"If you project this across the whole of internet retail, then millions of pounds worth of business is probably being lost each week due to simple spelling mistakes," says Mr Duncombe, director of the Just Say Please group.
Spelling is important to the credibility of a website, he says. When there are underlying concerns about fraud and safety, then getting the basics right is essential.
"You get about six seconds to capture the attention on a website."
When recruiting school and university leavers, Mr Duncombe says too many applications have contained spelling mistakes or poor grammar.
"Some people even used text speak in their cover letter," he says.
Even among those who appeared to be able to spell, he says that a written test, without access to a computer spellchecker, revealed further problems with spelling.
William Dutton, director of the Oxford Internet Institute at Oxford University, says that in some informal parts of the internet, such as Facebook, there is greater tolerance towards spelling and grammar.
"However, there are other aspects, such as a home page or commercial offering that are not among friends and which raise concerns over trust and credibility," said Professor Dutton.
"In these instances, when a consumer might be wary of spam or phishing efforts, a misspelt word could be a killer issue."
James Fothergill, the CBI's head of education and skills, said: "Our recent research shows that 42% of employers are not satisfied with the basic reading and writing skills of school and college leavers and almost half have had to invest in remedial training to get their staff's skills up to scratch.
"This situation is a real concern and the government must make the improvement of basic literacy and numeracy skills of all school and college leavers a top priority."