Market your content virally on social networks by forcing users to perform a social action before accessing your protected content.
Check out the 2 minute demo video on YouTube: http://www.youtube.com/watch?v=aheR3_ROt94
Like To Keep Reading is a WordPress plugin that forces visitors to Like you on Facebook to access content on your website.
You can protect entire pages or posts, or just sections of pages or posts (our favorite) – i.e. your visitors can read the first two paragraphs and then must click the Like button to keep reading.
You can force visitors to Like your website homepage, any sub-page/URL on your website, or your Facebook page.
Like To Keep Reading also has optional Google+ and Twitter integration – so instead of Facebook Likes you can get Google +1s and Tweets from your visitors in exchange for access to your content.
This plugin is available for download to be used on your WordPress self-hosted installation.