Over the past fifteen years, the so called ‘gruppi di acquisto solidale’ (GAS - solidarity purchasing group – see www.retegas.org) have flourished and currently over 750 groups are included in the national network database. How are these organizations organized? What is their political role? Is there any territorial differentiation in their organization and/or political functioning? These are some of the basic questions the paper will address by: first, identifying the specificity of the Gas with respect to the ‘classis’ definitions of social movements and interest groups; second, by analyzing the evolution of the Italian GAS, the paper will provide a tentative explanation for their explosion over the past years; third, the political dimension of the groups will be investigated and framed into a comparative perspective.