That is a really good question for debate. You may see my views on it here: http://www.quora.com/Microfinance/Do-the-micro-loans-contrib...
For example, can I use Zidisha to support people like Salamatu: http://www.kiva.org/lend/625549, or is Zidisha something I should use alongside Kiva to help the more fortunate borrowers?
Today, the generation just entering the working population in developing countries still live on pretty meager incomes, but unlike their parents, are commonly on Facebook and able to participate in an online community without any intermediation from local organizations.
Most Zidisha borrowers are young adults living on about a dollar a day in the urban slums of Africa and Asia. They often have high school degrees and many are enrolled in university, but they live in sheet-metal shacks in muddy streets lined with sewage. They help support their families by searching for low-pay day labor or selling small inventories of low-value items. They usually access our website via public cybercafes (the price to browse the internet in Nairobi is just about ten cents).
So to answer your question, to support Salamatu herself you would probably need to lend through Kiva or another local organization. But if Salamatu has children, they may well be raising their own microloans through Zidisha someday.
Here is a story about one of our members who operates a cybercafe in Nairobi, which gives a pretty good idea of how young adults in developing countries are going online: http://p2p-microlending-blog.zidisha.org/2013/06/12/life-wil...
I'm more intrigued by the disruptive prospect of getting foreign funds for people looking to set up SMEs in developing countries to raise people out of poverty by giving them regular employment, which seems to get less attention. (of course it's possible that's because traditional banking does an adequate job, but unlikely)
Microfinance as a poverty-fighting tool is hotly debated among donors. Here is a recent post about why we believe microfinance is healthier and more effective than handout-based charity: http://www.huffingtonpost.com/julia-kurnia/about-to-send-a-d...
But don't just take my word for it. I'd encourage anyone interested in what microfinance borrowers themselves say about their loans to check out our universal member comment feed. This is simply an uncensored feed of the latest 100 comments posted on Zidisha loan profile pages by our members worldwide. It gives some insight into the wide variety of loan uses and results, and how the borrowers themselves describe the impact of microloans in their lives: https://www.zidisha.org/microfinance/testimonials.html