Hello manfred wang!
Thank you for your great questions and sorry for my late reply.
1) I decided to show the general formula for CLTV to make a reader aware about the concept. However, due to data limitations, I decided to focus on the sales only, which I think should be directly related to CLTV. More a user spends - higher CLTV he/she has.
2) Regarding new customers, I think it's quite tricky to predict their CLTV becuase we do not know about their purchasing behavior. Therefore, I would exclude them from the anaysis and wait until we get enough data.
Hope I could answer your questions.
If you have any ides on the questions you asked, please share with me. I'd be happy to learn from you 😊
Also, I'd be happy to get connected with you on LinkedIn and keep in touch. My LinkedIn: https://www.linkedin.com/in/aigerimshopenova/