Email marketing armed with social media's power of sharing is increasingly used by fundraisers and associations. Nothing is stronger than a friend's recommendation.
While this works well for sharing with friends, ensure that your landing pages (where many donations happen) solicit email addresses as well, thus allowing your list to grow. This is a win/win situation, as the more 'friends' gets involved in donating, the more your opt-in list will grow, and the more people you can influence.
The sample here shows Susan G. Kormen's email promoting their fundraising application within Facebook. It is essentially a nice way for users to extend their fundraising efforts through their network of friends.
As many marketers start to adopt additional integration points with the leading social media sites (e.g. Facebook, Twitter, etc), they will also start to utilize email as a way of driving channel adoption. From adoption, marketers will turn to utilizing email for promotion usage and analyzing performance to fine-tune and improve their program through segmentation, personalization, and sophistication.
Today many marketers are simply focused on presence and adoption; however, it will serve them well to be thinking broader in terms of ultimately how to monetize these social media applications. This example by Susan G. Komen for the Cure is a testament to a marketer thinking several steps ahead.