The document introduces the Channel Diversity Index (CDI) as a new metric for measuring sales channel diversification. CDI calculates the distribution of sales across different channel partners, with a more even distribution indicating a more diversified channel. The document provides an example calculation of CDI for a mobile operator's prepaid sales through dealers. From 2007 to 2008, the operator's CDI increased from 7.04 to 7.68 as revenues distributed more evenly across partners including one new partner, demonstrating an improved diversification of its sales channel. CDI can help companies monitor channel diversification and power of individual partners over time to reduce risks from over-reliance on few partners.