By Paul Sandle LONDON (Reuters) – Wikipedia co-founder Jimmy Wales has taken a substantial stake in The Peoples Operator (TPO), a London-based mobile provider that pays 10 percent 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. 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 (MVNO), which means it relies on an existing operators network, in this case EE, the British joint venture between Frances Orange and Deutsche Telekom. Mark Epstein, chief executive and one of the companys 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.