I want to increase my 30 day LTV. Probably through email cross sells. Is there a boilerplate plan of attack on this? like day 7 after (original) purchase begin email sequence: Email 1 - Hi *customer - because you bought X, many Customers buy Y - here's a coupong -- Discount Y% offer Email 2 - 1 day later - Increase coupon by 10% Email 3 - 2 days later - expiring coupon for 25% off