Think about the customer personae. Who is your target customer/client?
The general manager of human resources or Corporate Social Responsibility (CSR) may or may not be interested in your offering vs passionate leader-agitator who is a junior manager but is enthusiastic to align with them and influence inside the organisation?
Try and enter through CSR or HR strategy with an offer of outsourcing, problem-solving, innovation or shared value.
Have a coffee with them and ask who should we look to reach out to, who do they work with and what kind of problems they are trying to solve, what kind of partnerships do they do (contact organisations and ask for advise on how to get into the sector). They could potentially turn to you and say this is us, and what can you offer us.
Go where they are. CSR, HR or Strategy Conferences, publications, professional networks, leverage an opportunity via a donor.