You can have a perfect CTA for showing Content, Products, Page Links, etc on the selected pages or all pages using a plugin called Easy Side Tab.
Easy Side Tab Pro is a premium WordPress plugin that allows you to create side tabs and stick them to the window edge. Clicking on the tab opens the associated layer. You can display Twitter feed, HTML content, products, blogs, custom shortcode, subscriptions, and social icons. Add the shortcode to the display tab for that page.
The Plugin allows you to add Call To Action Floating Tabs plugin for WordPress which allows you to create any number of quick side tabs and stick them to any of the vertical or horizontal edge positions. When the tab is clicked the popup associated with that tab pops out. The plugin has a very easy and user-friendly backend interface to create your tabs and assign different functions to each of the tabs.