Hello. Grace! First of all, thank you for the great lecture. I have completed all of the previous marketing lectures and this one as well! It was helpful because there were things I had forgotten about optimization and things I learned new. I enjoyed the marketing indicators the most, and I also enjoyed looking at the CAC and LTV. In particular, the marketing indicator examples for OKR were very helpful to me. Thank you. Both lectures seem to be the backbone of (performance) marketing. If you are a marketer or preparing for it, I think this will be a useful lecture. I recommend it!