Nonprofit organizations, with limited advertising and marketing dollars, should designate social media as the highest priority in their communications strategy. It always makes me sad to see nonprofits blowing thousands of dollars on outdoor boards when they could be focusing their energy on real, two-way conversations with constituents, prospects and donors online.
Think of the possibilities within these two channels alone:
Facebook is probably the most effective digital grassroots and organizing tool there is. If you're trying to rally people around a cause, there's no better channel than Facebook, where your volunteers can spread your message, and even organize events on your behalf. Barack Obama's grassroots fundraising efforts have proven how powerful a tight Facebook strategy can be.
Twitter's power exists in small geographic pockets, which could really benefit a small nonprofit that only wants to reach a local audience. Imagine the impact the Animal Rescue League of Iowa could do on Twitter, reaching out to a Des Moines area audience with 140-characters "tweets" featuring a new animal that needs to be rescued, every day. All it takes is a little wordsmithing and a twitpic account to show off the animals' mugs.
A huge benefit here is what it costs - next to nothing. It's free to interact within these channels, but there is going to be a required time commitment to immerse yourself, learn the mediums and participate properly within them. Like any successful communications strategy, you get out of it what you put into it.