By Clare Davidson Business reporter, BBC News It all started when Joyce Wafukho, then in her early 30s, spotted a gap in the market in her village in Kenya. "There was no hardware store," explains Mary Ellen Iskenderian, who first visited Ms Wafukho after becoming head of the non-profit organisation Women's World Banking in September 2006. "After borrowing from family members and scraping some savings together, she started selling nails and screws from a kiosk." She also sold tomatoes, "not your standard DIY stock," laughs Ms Iskenderian.

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