WordPress, being a giant in the Internet market share, has become a very attractive selling platform to software companies and freelancers. As of writing, 47,502 plugins with 1,451,198,607 total downloads have been registered to wordpress.org – and these are just the free plugins hosted by WordPress. The amount of premium plugins and themes can only be estimated, but fact is that a lot of financial potential is lying in premium plugins and themes. > WordPress is used by 58.6% of all the websites whose content management system we know. This is 27.0% of all websites. w3tech, November 2016 However, developing and selling a premium WP product turns out to be not very easy. Especially if you want to provide a free version hosted in the WordPress repository (you should). There are some hurdles to overcome regarding WordPress policies, security and developer experience. I want to share our experiences and gained knowledge while developing and deploying our products Photography Management and Ultimate Ads Manager. Because there is quite a lot to handle, this post will be split into three parts: – Free WordPress Plugin with In-App Purchase – DRY code sharing of free and premium – Release your Premium WordPress Plugin Update