Niche! If you’re talking to everyone, you’re talking to no one!

I’m struggling with my niche!! I have a 6-year old PR/Social Media Agency (Creating and posting content) business with a 50-50 business partner. We’ve decided (100% committed) to launching a consulting brand as a new arm of this business. It is where we have always wanted to take the company, and we’re in agreement that now is the time. I’m almost done with our new website, copy, services and something is missing… the niche! We decided that we offer “Digital Marketing Consulting to businesses with value-driven culture” … I’m worried that is too vague/not niche enough. My dream client would be marketing consulting for local non-profits (but corporate sized – not start ups – think, Habitat for Humanity, etc.). However, my biz partner doesn’t feel the calling to non-profit the way I do, and also has concerns that NP’s don’t have the budget we need. And, also feels that if we are too specific we will be missing out on all the tech companies in our city. I’ve listened to all of your advice on this and my gut says we are talking to everyone aka no one and we have got to be more specific on our niche. How can I do that with a business partner who isn’t exactly on the same page? thank you!