Licensing: Pros and Cons of 100% GPL and why we Made a Switch

The motivation for writing this post was an email that I received couple of days ago: I am starting an online workshop for business owners who look to build their own website’s code for free. So I wanted to create a bundle package which included a theme, I like the CargoPress theme and it says that it is 100% GPL. Would I be able to include it in a bundle package I will be selling? Please help I am lost when it comes to understanding what you can do with GPL.
This was the first time I’d received this type of question/request, and the timing of it was just perfect. For quite some time now I have wanted to share with you the path that led me to the decision to license all of our WordPress themes under 100% GPL.
How to license premium WP products has long been a debate in the WordPress community, it has also led to many #wpdramas. We tried to delay our licensing decision for as long as we could, but now that we have launched our new website (with our own shop), we couldn’t prolong it any further.
Four years ago, when Jaka and I started ProteusThemes – as with most newcomers to this field – we didn’t pay much attention to the licenses. We didn’t
Source: https://managewp.org/articles/13556/licensing-pros-and-cons-of-100-gpl-and-why-we-made-a-switch

source https://williechiu40.wordpress.com/2016/10/06/licensing-pros-and-cons-of-100-gpl-and-why-we-made-a-switch/