Having read the open software license, I decided that it is time to learn more about different editions of Magento (Community, Professional & Enterprise).
The best edition I liked is the Community one, because I am not used to pay for software, and of course not for open source software. Although It is obvious that the companies have to pay for the Commercial License, Warranty and Payment Services. In my opinion, the interface of Magento is very simple and user friendly. The sections in the program are also very well classified. My first Magento exercise was to write an instruction for a Magento customer about how to get started with Magento. In order to accomplish this task, I had to look around in the back-end in order to write the instruction in a good sequence. It took me about 6 hours to learn how to add a product in the back-end of Magento. The instruction included such items as how to add the categories, attribute sets, attributes & finally products. Having got the first lesson, I am looking forward to the second one, for which I will be waiting the whole weekend;)
Recently I've seen some (often absolute) statements going around, generally in the line of "open source commerce platforms are a terrible idea". Now of course different solutions always have different pros and cons.
A hierarchy of evidence (or levels of evidence) is a heuristic used to rank the relative strength of results obtained from scientific research. I've created a version of this chart/pyramid applied to CRO which you can see below. It contains the options we have as optimizers and tools and methods we often use to gather data.