Reality: This is a common refrain for CFOs, heads of ecommerce and other executives who view email as a low-cost delivery channel rather than a strategic relationship conduit.

"Send it again!" they say when they see how well an email campaign performed. They treat email like the old direct-mail model of mailing: send and send until the cost of sending to a list no longer breaks even.

But email is different. Consumers and the ISPs control the ecosystem. Yes, increased frequency can often deliver short-term results. But it also increases list churn through higher spam complaints and unsubscribes and, subsequently, higher acquisition costs to replace the lost customers and revenue.

Instead of just pounding their lists with the same old offers, marketers can use email to drive more sales or conversions by moving to a more personalized and targeted approach. Lifecycle, drip, trigger- and behavioral-based approaches will reduce list churn and improve the ROI of your email program.