Wikipedia co-founder Jimmy Wales has taken a "substantial" stake in The People's Operator, a London-based mobile provider that pays 10% of revenue to good causes, with the aim of taking it to the United States and other markets.
Wales said TPO had pulled off the difficult feat of creating an inspirational business that had solid commercial foundations.
"Its big vision is to generate massive sums of money for good causes," he said in a telephone interview.
"But when I worked though the numbers and looked at the business model, it made a lot of sense to me."
TPO is a so-called mobile virtual network operator,which means it relies on an existing operator's network, in this case EE, the British joint venture between France's Orange and Deutsche Telekom.
It launched a pay-as-you-go operation in November 2012 and followed in April 2013 with a contract offering unlimited voice, mobile and data for £14.99 a month.
Ten percent of revenue is directed to any good cause chosen by the customer and the company also pledges to pay 25% of its profits to charity.
Mark Epstein, chief executive and one of the company's founders, did not reveal customer numbers, but said there had been a rapid increase in take-up since it introduced its unlimited deal, from which hundreds of good causes were benefiting.
TPO, which is not yet profitable, does not spend huge sums on marketing, Mr Epstein said, relying instead on word-of-mouth and promotion by the organisations it helps.
Mr Wales, who launched online encyclopaedia Wikipedia 13 years ago, said he would help TPO expand internationally, starting with the United States. He will be co-chairman of the company.
"We need to go global as quickly as possible," he said. "We will really push into other markets as soon as we can get deals done."
He said he would also help create a louder online buzz for TPO. "One of the reasons they were interested in me is to really build that online community - an online offer that has all the tools they need to accelerate virally."