General operating support grants allow nonprofits to target resources where they are most needed and will be most impactful. Lots of great info in this article from a foundation that has learned that general operating support grants enhance effectiveness and impact while building deeper relationships. 

“Now that every one of our grants is for general operating support, we see the depth in which we are able to learn from our grantees. We also see the successes that come when organizations feel trusted and have the flexibility to make decisions on how to best fulfill their mission at any given time.“

http://cep.org/the-case-for-general-operating-support/