Shopkeeper Heraldo Rodrigues da Silva, 55, owns a small store in Sao Benedito, one of the poorest neighbourhoods in Vitoria, the capital of the Brazilian state of Espirito Santo.
On the wall behind his counter, a sign announces that besides the real - Brazil's legal tender - he accepts the "bem", an alternative currency from a local community development bank, Banco Bem.
The bank was founded in 2005 by an association of seamstresses who decided to lend their profits to a group of furniture makers so that they too could start their own collective.
There are some 100 similar microfinance banks in Brazil, as well as many barter initiatives that also involve social currencies. The banks' aim is to promote the principles of a "solidarity-based economy" which, in their view, is fairer and more sustainable than the dominant capitalist model.