timsoulo

Content Upgrades plugin will help you to create “content specific bonuses” in your articles, that people have to opt in for.
How does it work?
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The plugin gives you a shortcode that you can use to create a basic text link anywhere in the text of your article.
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Once your visitors click that text link, a popup will appear, asking them to leave their email address.
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Once they submit their email address, they will get redirected to the page of your choice.
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Get the PRO version at: <a href="http://contentupgradespro.com/" rel="nofollow ugc">http://contentupgradespro.com/</a> 
– unlimited number of “content upgrades“; 
– 5 new design templates of popups; 
– option to turn off Double Optin; 
– automatic bonus delivery by email.

Content Upgrades

Use this plugin to create content upgrades, which require your readers to subscribe to your email list to get access to the bonus materials.

ichurakov

Twitter Content Locker plugin is a good solution for website promotion via Twitter. With this plugin you can hide part of your content (for example, images, download links, passwords or other important information) from users. User must share your page on Twitter to view hidden content. Check out <a href="http://www.icprojects.net/twitter-content-locker.html" rel="nofollow ugc">working demo</a>.
Install the plugin and wrap any “secret” content with shortcodes [twitterlocker] … [/twitterlocker].
You also can extend standard shortcode by using attribute “message”. Example: 
[twitterlocker message=”Type any message here to replace default message by yours!”] … [/twitterlocker]
Type shortcode manually or use special button with your WYSIWYG-editor to insert Twitter Content Locker shortcode.
For more details please visit <a href="http://www.icprojects.net/twitter-content-locker.html" rel="nofollow ugc">Twitter Content Locker</a> plugin page.

Twitter Content Locker

The plugin allows to lock part of post/page. User must share it on Twitter to view the content.

Content Upgrades vs Twitter Content Locker