Having worked in a large non-profit, I'd need to know whether your product aligns with the mission and the goal priorities of our organization (the first hurdle). You might be surprised to know that non-profits get approached about being involved in a lot of things. Whether something is "free" or not, it still requires mission alignment, and staff time to consider and act on.

If I was hooked on it's ability to support the mission/our goals, I'd then need to evaluate the time to implement and upkeep (the second hurdle). The primary question in this setting is "Can we take action on it today without any additional cost and minimal staff time?" Effective non-profits are very mindful of scope creep. They want their staff to be working toward their respective goals as much as possible since the general public evaluates their effectiveness on money spent on programs/overhead.

Hope this helps you tailor your outreach!