This research was published more than 5 years ago, some information may be out of date.
On overview of Citi's work in Microfinance written by author Robert Annibale, head of Citigroup MicrofinanceGroup.
From report:
"Long associated primarily with philanthropy, leading microfinance institutions are demonstrating that they are sustainable and scalable providers of financial services to poor and underserved communities, attracting the interest of a wider spectrum of investors - including banks, specialized funds and even technology billionaires."