If you’re an ecommerce marketer, email marketing should be your best friend. Email consistently outranks other digital channels such as social media and display ads in terms of return on investment. A VentureBeat Insight study found that email marketing generates an average of $38 for every $1 invested.

The problem is that’s just an average. Not every ecommerce store’s email marketing is going to be churning out $38 for every dollar spent on it. And, more concerning still, not every marketer[...]