Blackline came to us with about 20,000 subscribers sitting in Klaviyo and no way to reach or grow them: no signup form, no segmentation, and roughly one campaign a month sent as a one-off. We built the program in order, starting with the signup form so the list had a mechanism to grow, then the flow architecture so revenue stopped depending on manual sends, then offer testing, a real send calendar with a reason behind every email, and optimization against performance data. Klaviyo attributed revenue went from $28,365 in July 2025, the month before we started, to $288,370 in May 2026. The list grew 4.5x and revenue per subscriber grew 2.3x on top of it, from $1.42 a month to $3.20, which means more than half the gain came from subscribers getting more valuable rather than more numerous. The automated layer alone now produces about $4,206 a day, up from about $458, and the SMS welcome flow runs at $15.50 revenue per recipient against a $0.12 platform average.