While the growth of mobilecommunications in developing countries has been phenomenal,using mobile phones and applications to meet human andeconomic development goals is not widespread, for they havenot proven acceptable or desirable to the locality intowhich they are introduced. Therefore, it is deduced thattechnical know-how and entrepreneurial acumen must becomplemented by sociocultural understanding. InfoDev'sMobile Use at the Base of the Pyramid program seeks tocontribute to this agenda through on-the-ground studies indeveloping markets. The first phase of this programsupported both qualitative and quantitative research onmobile usage by low-income populations in Kenya and SouthAfrica. This report documents the findings of this program.