The most important rule: lead with the achievement, not the intent
The most common mistake in cover letters is the opener "I am writing to apply for the Marketing Manager role posted on Indeed". That sentence adds nothing the reader doesn't know — they're already reading your application, they already know the role. Wasted paragraph. The modern professional rule: open with concrete data about you. Your most relevant achievement. A number that matters. A specific observation about the company that proves you researched.
Four opener styles that work
- Achievement-led. "Over the last three years, I led the launch of a product that generated $2M in its first year." Works when your record speaks for itself.
- Why this company. "I've followed [company]'s work since 2020, and what stood out most was your decision to [concrete fact]." Works for companies you genuinely admire.
- Internal referral. "[Name], head of [area], suggested I apply after we discussed [topic]." Works when you have a real referral.
- Research finding. "Reading [company]'s last quarterly report, I noticed segment [X] grew Y%. My experience in [area] aligns directly with that growth." Works for analytical roles.
Data that DOES belong in the intro
- Tangible numbers. "20% increase", "10 million users", "$500k budget managed".
- Recognizable names. If you worked at well-known companies or studied at top programs, mention it briefly.
- Time. "Over 5 years at X" gives more context than "I have experience".
- Comparative scope. "Team of 3 I scaled to 12" tells more than "led a team".
Data that does NOT belong in the intro
- Your name (it's on the resume).
- The role you're applying for (they know).
- Where you found the posting (irrelevant for evaluation).
- Your availability (that goes at the end, if anywhere).
- Begging language ("I would appreciate the opportunity to", "looking forward to your prompt response").
Recommended length
The ideal intro is 2-3 sentences totaling 35-60 words. Enough to plant a strong data point and steer the reader to the next paragraph. Longer dilutes; shorter feels truncated. If your best achievement doesn't fit in one sentence, use two — don't compress past clarity.
Tailor to the role
The achievement you put in the intro must connect with what the role asks for. If the posting says "experience leading remote teams", your intro should include a number about the size of the remote team you led. If it says "ecommerce experience", your intro should carry an ecommerce metric. That alignment is the difference between 100 identical letters and yours.