What are common copy mistakes that tank performance?
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Most copy mistakes that hurt email performance don't show up at the word level. They show up in decisions made before you wrote a single sentence: the wrong message for the moment, a CTA that asks for too much too soon, or a subject line that promises something the body doesn't deliver. Knowing what to look for makes these preventable.
The most common offender is writing for yourself instead of your reader. This shows up as emails that lead with company news ("We're excited to announce..."), benefit lists that describe features instead of outcomes, and CTAs that say "Submit" instead of "Get my discount." Your reader's first question is always "what's in it for me?" If your copy doesn't answer that in the first sentence, you're already behind. The fix: swap the subject of your opening sentence from "we" to "you" and read it again.
The second most common mistake is sending the wrong depth for the moment in the relationship. A cold welcome email that tries to explain your full product line loses readers who haven't decided they care yet. A re-engagement email that's just one line with a button feels jarring to someone who's been on your list for two years. Matching your copy's depth and tone to where the reader is in their lifecycle stage is where most of the real performance gains live.
Other high-impact mistakes: subject lines that don't match the email body (which spikes spam complaints when readers feel deceived), broken personalization tags that send "Hi {{first_name}}," to your entire list, skipping mobile preview before send (a paragraph that looks clean in your ESP's editor can render as a wall of text on a phone), and burying your CTA below the fold when readers who would have clicked never get that far. Each of these is a vote against your engagement signals, and engagement is what keeps you in the inbox long-term.
Before your next send, run through four questions: Does the subject line match what's inside? Is the CTA visible on mobile without scrolling? Does the email open with "you" or "we"? Is every personalization tag tested with a real record? Catching one issue before send is worth the 30 seconds it takes to check.
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