At the heart of Klaviyo’s success is its ability to use customer data to drive meaningful, revenue-generating email marketing. By tapping into behavioral data, past purchases and engagement patterns, businesses can send timely, personalized messages to each individual customer. The end goal? To nurture the customer journey and encourage repeat purchases by building real relationships through email. Still wondering why email marketing is so important? Despite the rise of social and paid media, email still delivers the highest return on investment. In fact, many businesses using Klaviyo see email accounting for 20% to 50% of their total revenue.