It gets the highest return (amount back compared to how much you spend) because the cost is low, and if used correctly, generate a lot of sales.
For example, this food store we work with. Each of the big sales peaks is an email going out to 3,500 previous customers.
The example above is from sending 3 simple emails, 1 a week, with messaging about new products in high demand being available.
The 2nd email (biggest peak) had a 20% off a specific product they were over stocked in. Note the promo was to clear a product with too much stock, not just a blanket 20% off (that just kills your profit).
What not todo
The above examples were send to customers who had showed some type of interest. Basically don’t email everyone on your list. That will see your open rates drop and subsequently sales.
If you’re new to email marketing, it’s time to start reading up on it and investing your time and energy in it. You won’t be disappointed!