Don’t talk down to people. I think this should be obvious. But looking at the email offers I get, clearly it isn’t. Don’t tell people, “Not buying this product would be idiotic!” or “Only a fool doesn’t understand the value in this service.” This whole email marketing strategy relies on you making people understand the value they can get from you. And sometimes that means making people see the downsides of not buying. But you can do that in a friendly, respectful way.
The downside of just making offers is that they’re not useful on their own. People on your list won’t receive any value from you unless they buy what you’re promoting, so they have little reason to stay subscribed. That’s why this email marketing strategy doesn’t work alone. And it’s why many e-commerce sites struggle to keep people interested. There are a few exceptions (e.g., Groupon) that rely entirely on making offers—but then the reason people joined the list was specifically to receive those offers.
The primary cost of poorly crafted or mis-targeted emails is lost business opportunities, though in extreme cases it can damage a firm’s reputation as well. But the potential payoff for effective email marketing is substantial; email messages are more likely to be seen and acted upon by decision makers than online content, social media, or advertising.