Different sidebars or widget areas in the footer, for different posts or categories, is a very cool and in my opinion overlooked possibility in WordPress. It allows for more dynamic and relevant content in the posts, a feature that’s normally only available in premium theme builders.
Extract from WordPress.org
You can optimize conversion rates, boost on-site SEO, upsell products, and much more by displaying different widget areas on different conditions. Replace your theme sidebars on different conditions, or insert widget areas with shortcodes. With the All-in-one Sidebar Manager, you can easily activate and deactivate widget areas, and you can even schedule them for specific times.https://wordpress.org/plugins/content-aware-sidebars/