I would suggest the first question to ask is "what problem do I solve?" And of those people I solve problems for "who do I create the most value for?" In the non-profit world you need to add "How does my business help the non-profit run better and/or help the group the non-profit focuses on?"
For example, if you've created a platform that drives donations, your company "has created a platform that helps you reach fundraising goals faster."
What you don't want to do is market and sell to B2B and B2C audiences simultaneously. They have different ways of buying - a B2B audience needs to have their benefits quantified (using your thing makes me x amount more) - and it's extremely hard for a startup to be able to do both well. Better to start with one, execute really well and move into the other.
Feel free to give me a call and we can dig into who your most valuable audience is.