To get the best experience and understanding of SocketPro, it can help to have a better understanding on how the Chinese internet works.
China has it's internal internet structure. This internet within Mainland China is nowadays quite fast and provides good performance. So a person in China visiting a website hosted in China has a great experience and no speed limitations.
Then at the borders of China there are connection points to the internet outside of China. At these exchange points the Great Firewall of China is implemented*, from now on referred to as GFW. This firewall blocks services such as Youtube and Facebook, but also does on demand analysis and filtering based on keywords, IP addresses and more.
You could see the GFW as a big bouncer at a club. All the party people are lining up to get into the club and the bouncer does a strip search for each single person every time they go in or out of the club. This creates quite the queue and slows down the whole process.
So when visiting an unblocked international website from within China, your request still goes through this whole system and therefor has bad performance and slows down significantly.
This is where SocketPro helps. Our system encrypts your connection and by doing so it can not be analysed and filtered, so you can completely skip the body guard (GFW) at the door of the club.
It is also interesting to note that there are only a limited amount of "exit" points in China where the requests for international websites leave the country. Below is an image of the known "exit" points in China. This data is somewhat dated and comes from a presentation from 2012. More points and improvements have been made over the last years**.
As you can see from the image, depending on where you live in China, there are certain location that are better to connect to then others.

* Source: (https://en.wikipedia.org/wiki/Great_Firewall)
** Source: https://www.forbes.com/sites/lisachanson/2015/02/24/the-chinese-internet-gets-a-stronger-backbone/