Ron Rennick

Uses a custom post type to allow editing of the promotion(s). The most recent published promotion post by date is shown below single posts.
Some (CSS tips)http://wpebooks.com/free-plugins/genesis-promotion-box/ for your child theme.
Requires the Genesis Theme Framework.

Genesis Promotion Box

This plugin allows you to add a promotion box after a single post in Genesis.

Code Tides

Advanced Floating Content: The Easiest Way to Add Sticky Content, Popups, and Banners to Your Site.
With over 8,000+ active installations, the Advanced Floating Content Lite plugin is the all-in-one solution for adding sticky headers, footers, social sharing buttons, and promotional banners to your website. It’s easy to use and provides all the tools you need to create engaging, professional-looking floating content without touching a line of code.
Whether you need to display a site-wide notice, embed a video, or add a sticky social media bar, our plugin makes it effortless.
<h3>Key Features (Lite)</h3>
<ul>
<li>Unlimited Floating Content: Create as many floating elements as you need—no restrictions!</li>
<li>HTML Codes In Your Control: Use the WordPress editor to create custom HTML and CSS for your floating content.</li>
<li>Video Embedding: Easily embed videos from YouTube, Daily Motion, and Vimeo that float anywhere on your site.</li>
<li>Social Media Sharing: Add social media sharing icons for Facebook, Twitter, and LinkedIn with a single click.</li>
<li>Fully Responsive: The plugin automatically adjusts to fit any device, including mobile phones and tablets.</li>
<li>Control Impressions: Enable control impressions to prevent content from showing again after an end-user has closed it.</li>
</ul>
<h3>Get More With The Pro Version</h3>
The Lite version is just the beginning. Upgrade to the Pro version to unlock powerful features that give you complete control over your floating content, allowing you to boost engagement, drive sales, and capture attention.
<ul>
<li>Advanced Targeting: Show content on specific pages, posts, or categories, including WooCommerce products and bbPress pages.</li>
<li>Display Latest Posts: Automatically display a list of your latest blog posts inside your floating content.</li>
<li>Show WooCommerce Products: Showcase individual products or product categories directly within a floating banner.</li>
<li>Display Control: Show or hide content based on screen size (width and height).</li>
<li>Animations: Grab attention with stunning loading and closing animations.</li>
<li>User & IP Filtering: Show content only to logged-in users and build an IP blacklist to exclude unwanted visitors.</li>
<li>Scheduling: Automatically schedule your content to start and stop at specific times.</li>
<li>Custom CSS: Apply custom styles for both mobile and desktop views.</li>
<li>Sticky Elements: Transform your floating content into a sticky header or sticky footer.</li>
<li>Custom Close Buttons: Use custom anchor tags to close content without a visible button.</li>
</ul>
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Advanced Floating Content Lite

Advanced Floating Content Plugin is an all in one plugin with easy to use controls, helps you demonstrate sticky footer or header with many features.

Genesis Promotion Box vs Advanced Floating Content Lite