I don't think it is a 'perfect balance' so much as trying to maximize the number and length of advertisements that people will tolerate at this point in time. T

I don't think it is a 'perfect balance' so much as trying to maximize the number and length of advertisements that people will tolerate at this point in time. The nature of the business model is that some product manager will be tasked with getting the advertisement revenue higher at some point in the future and they will no doubt try to push the envelope. I also feel like 'total view time' is a metric that is in service to advertisements and not the primary goal itself.