Disclosure: Some of the following links are my affiliate referral links to a third party service, if you click on the link and purchase the item, I might receive a commission. In many cases, I have a developer license and can upload the theme for you, otherwise you would need to purchase a license, and if you use my referral link, I could apply the commission to upload the theme for you. Please contact me to assist you.
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Developers offering premium WordPress plugins and themes tend to stand behind their plugins and provide good customer support. This is a rarity for free WordPress plugins or themes in most cases. A free product developer can’t really stand behind his product and answer your questions if he is not getting paid in some way.
Free WordPress plugins or themes are sometimes developed by hobbyists who do not have a good grasp of WordPress’s coding guidelines. This can result in a poorly coded product with potential security holes.
Also, good premium products are usually developed by knowledgeable coders who keep the site performance in mind when developing the product. This ensures that your site’s performance won’t go down after you install.
Continued Development and Updates
Premium WordPress plugin and theme developers usually continue to update their products’ coding to fix bugs, add features and improve the overall design to keep up with current web trends. You usually get these updates for free.
Premium WordPress plugin and theme developers will also keep the product up to date with the latest release of WordPress. This ensures that you won’t get stuck with an incompatible product down the path and no chance of getting any help.
Premium WordPress plugins and themes usually offer more functionality and has superior back-end usability. This can give you an immediate advantage over your competitors.