Both Republicans and Demoncrats are aggressively using social media trying to convince swing voters.
It isn't working.
Social media is a wonderful tool to connect you to your biggest fans, but it's not working very well - especially banner ads - to change anyone's mind.
The lesson for radio: sure, try hard to maximize the size of your Facebook and Twitter communities, to make use of those people who know about and want to interact/engage with you to reach their friends who may be a lot like them (and, thus, YOU).
Truth: don't expect asking folks to 'like' you or 'follow' you will grow your cume very much.
It's content that draws new listeners and social media fans.
Focus on creating interesting, entertaining, engaging content.