I'm not sure whether it's appropriate to just jump in here as I've only just discovered this website but this I think in relevant to both ROI and SROI.
First I think I should mention Peter Burgess, of the Transparency and Accountability Network who's been doing quite a lot in the area of impact assessment.
We go back to origins in the US, which began with a pitch for a new approach to capitalism.
In 2006 having established in the UK as a social enterprise, we put a paper to the US Senate Committee on Foreign Relations, proposing a multi-component development strategy. For reasons that I hope will become clear by reading it we describe it as a microeconomic 'Marshall Plan'
4 major components in this plan combine, each with a SROI element and varying degrees of ROI, from full to less than full cost recovery. This gives an overall strategy designed to achieve nil overall cost in terms of financial investment.
target="_blank">http://www.p-ced.com/projects/ukraine/national/
One of the first resonses to the paper came at Davos 2008, in the creation of the East Europe Foundation, to promote CSR and support sustainable community enterprise, as recommended in the social enterprise component of the paper.