Nearly one in five Brits has never been online, says Martha Lane Fox.
Research by the Lastminute.com founder, who was hired by the government in June this year to run a Digital Inclusion team, revealed that nearly half of those can't get online due to their economic, housing or employment circumstances.
Lane-Fox also said that homes without internet access are losing around £560 per year because they can't pay bills online or shop around for the best deals. Furthermore, the 1.8 million children that are currently growing up in a digitally excluded home could lose out on £10.8bn in lifetime earnings by not becoming technology-savvy.
She also said that being internet literate can on average increase a person's earnings by as much as £8,000.
The savings don't only affect consumers. The government could save at least £900m a year if it could communicate with all Brits electronically, in areas such as job seeking, as opposed to face-to-face.
"I think it is really important to show the economic argument behind getting people online. By being online there are massive savings for people personally, rich rewards for their career prospects and also big savings for the government," Lane-Fox told The Telegraph.
She also suggested that if soaps such as Eastenders and Coronation Street feature story lines involving the internet, unconnected Brits might be convinced to get online.
She told the BBC "the jury is still out" on whether broadcasters would adopt such a storyline.
See also: Digital Inclusion PCs stolen in burglary