There is no doubt that many poor people handle a vast amount of financial transactions in their everyday lives. They borrow and lend from and to friends, extended familiy and informal lenders.
Thus financial services are there, with or without the formal microfinance institutions. The question is: Which difference do the informal institutions or mechanisms make?
Views differ. Some, like Michael Schreiver, a researcher from the US, believe that microfinance can learn a lot from the information sector. Others, like Ishengoma & Kappel form the German GIGA, believe that both sectors matter in their own way while Diana Farrel from McKinsey believe informal enterprise is mostly bad for growth.