You are missing on channel art, like, all together, feel free to message me on Skype at yangy.young and I can give you a hand with that for free
Your thumbnails are mainly stock images with watermarks. Once again I can help you with that
Your videos themselves are actually really good!
To begin, your about section could use a detailed description and the txt: Best Channel in the History of Dota? I smell a huge Ego...
As saud above your thumbnails, avatar and Banner need some work. A Custom made one to fit with your channel could improve it alot.
Making a channel trailer could attract non subs.
And lastly your video titles needs some work...