When do you know you're finally done with optimizing in growth? Brian Balfour explains the one guiding principle behind the best growth strategies and teams: Systematic growth is iterative due to 4 factors... 1. Product evolution 2. Audience shifts 3. Channel changes 4. Tactic fatigue The second part of the essay presents 5 strategies to "embrace constant change" and beat fatigue, saturation, and flat (aka zero) growth.