Hello, Mr. Shin Jae-hoon! First of all, I apologize for not being satisfied with the content of the e-book. I have always prided myself on the fact that there is no other course that provides this kind of information at this price, and many of the students who have taken the course have said that it is worth the 33,000 won, but it is true that I am a little embarrassed to hear that it is not worth the price. However, thank you for your valuable opinion! The e-book contains over 100 links, and I have only introduced the truly useful links among the over 2,500 development contents I have consumed over the past two years. If you have already searched these links on Google and YouTube, I think you can easily judge that my e-book is not worth the price. Also, as for the part where you said that I did not absorb the provided links and only gave the links, I did not write the e-book without absorbing the contents, but rather provided them in the form of links because it is inefficient to write all the contents of the over 100 links in the e-book. The articles in the links have already been organized once by the authors. That's why, rather than organizing and condensing those texts into this e-book, I provided them in the form of links so that you can properly understand the original author's intentions and detailed explanations. I think it's a misunderstanding that comes from the fact that if you read the added links properly, it's like reading hundreds of pages of text, whereas the e-book is only 74 pages long. As for the part where you said, "I'll give you a link and go and look...," I hope you understand that I added links to texts that would be helpful if you refer to them for each topic and content, and I didn't sell the e-book by listing links that aren't related to the content of the e-book. Rather, I and Infraon should have introduced the e-book as not suitable for people like Mr. Shin Jae-hoon who already know a lot of information in the e-book introduction so that they wouldn't buy it. I apologize for not thinking about that part. In terms of pricing for e-books, I checked the tuition fees of lectures on similar topics to my e-book by referring to all other lecture platforms, and set the price at the lowest price among them. However, I know that the format of e-books is more sensitive to price than video lectures. Therefore, I think you may be dissatisfied with the price because you have already found out a lot of information + the format of e-books + there are many links. However, I am still confident that the content of this e-book provides more than 33,000 won worth of value to non-majors who want to jump into the path of becoming a developer. Jaehoon was dissatisfied because he already knew a lot of information, but as you can see from other course reviews, there are many non-majors who do not have proper information, advice on how to get a job as a developer, and the direction of their studies. (I was one of them) I wrote this e-book for such non-majors, and although the content of the e-book does not cover all parts of the process of becoming a developer, I am confident that it is difficult to find a lecture that provides this much information at this price. I am confident because I have taken almost all the lectures on other platforms, but if there are any lectures that I have not heard of, please let me know. If there is anything you were curious about and you regretted not being able to find it in the e-book, please let me know in the KakaoTalk 1:1 Q&A room, and I will do my best to help you! If there are things I do not know, I will ask other developers directly and give you the answers you want! You can access the KakaoTalk 1:1 Q&A room anonymously, so please feel free to ask questions and give me the opportunity to compensate for your regrets and anger about the e-book! I am sorry that I could not satisfy you, and thank you for your valuable opinion! :]