I have been saying from the very beginning that you won’t be able to prove ROI for your investment in a social network if you try to get beyond the initial listening and reacting. This is one of the main reasons why organizations have not gotten past this point: they are being asked for a return on investment that is not there, cannot be calculated. You can do some calculations for basic functions you will perform – but there is nothing really that talks to the infrastructure investment.My answer has always been: you won’t get an ROI, but you need to invest on it as if it was infrastructure. Who computes an ROI for more storage? or an additional laptop? a printer? Those are infrastructure components that your organization must have and you just invest in them without expecting a specific return on the investment.