When speaking with nonprofits about their use of social media, I can never overstate the need for them to think about who it is they are communicating with via the different mediums, and how to frame the message in a way that will interest that specific audience. Market segmentation is key. If the Tweet or post is not framed in a way that will interest the reader, they will not click on it. This article gives nonprofits some ideas about broader topic areas, but the framing of the post is still key.
7 Things Nonprofits Can Talk About in Facebook Besides Themselves