Cold email personalisation has become the make-or-break factor in B2B outreach. Campaign Monitor found that personalised emails deliver six times higher transaction rates than generic ones. Yet many sales teams still struggle to consistently create compelling opening lines that grab attention.
This is where GPT-4o, OpenAI’s latest model, can transform your process. With the right setup and training, GPT-4o can generate personalised first lines at scale—helping your team save hours of research while boosting response rates.
Why First Lines Matter in B2B Sales
Business executives receive more than 120 emails a day. Whether your message gets opened or ignored often depends on the very first line.
Generic openers like “I hope this email finds you well” immediately signal mass outreach. By contrast, a first line that references a recent company achievement, a market trend, or the prospect’s role can increase open and reply rates by as much as 50%.
Effective personalisation requires awareness of your prospect’s business challenges, recent developments, industry context, and professional background. That’s where GPT-4o can help.
Setting Up GPT-4o for Personalisation
To get started, you’ll need access to GPT-4o via OpenAI’s API or ChatGPT Plus. The first step is designing a strong prompt template. This prompt should spell out your value proposition, audience, tone, and the type of personalisation you want.
For example:
“You are a B2B sales expert writing personalised email opening lines. Your goal is to create short, engaging, professional openers that reference specific company information. Keep the tone conversational but suitable for C-level executives.”
Feeding GPT-4o With Prospect Data
The AI is only as good as the inputs you provide. Include structured prospect data such as:
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Company name, sector, and size
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Recent news or press coverage
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Growth signals like hiring activity or funding rounds
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Key technologies used
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Social content or thought leadership pieces
Formatting matters—short bullet points or clean lists make it easier for GPT-4o to identify angles for personalisation. Salesforce research shows that sales teams using AI-powered personalisation see 37% higher win rates than those relying solely on manual research.
Prompt Engineering for Better Results
Think of prompt engineering as guiding GPT-4o to behave like your best-performing SDR. Structure your prompts in four parts:
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Context: Define the role and goal (e.g. “You’re a sales rep writing first lines for outreach emails”).
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Prospect info: Insert structured data about the company or individual.
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Style guidelines: Specify tone, word count, or formality.
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Output instructions: Request multiple variations, or ask it to avoid clichés.
For even better results, show GPT-4o examples of strong first lines (“few-shot learning”), or provide negative examples to steer it away from generic openers.
Testing and Refinement
Even with strong prompts, you’ll need to test and refine. Run A/B tests on different personalisation approaches and measure their impact on open rates, replies, and booked meetings. HubSpot found that teams using structured A/B testing improve email results by 37%.
Scaling Across Your Team
Once you’ve identified what works, roll it out across your sales organisation. Build prompt libraries for different industries, set up light-touch quality control, and integrate GPT-4o with your existing outreach stack (CRM, LinkedIn automation, email platforms). This allows your team to generate hundreds of personalised lines daily while staying consistent.
Measuring ROI
Success should be tangible. Track the time saved compared to manual research, response rates versus generic outreach, the quality of conversations generated, and the acceleration of your sales cycle.
McKinsey reports that advanced personalisation strategies can increase revenue by 15% on average. With GPT-4o, the lift comes not only from better emails but also from freeing your team to focus on relationship-building and closing deals.
Final Thoughts
GPT-4o isn’t a magic bullet, but with the right data, prompts, and testing, it can dramatically improve the scalability and quality of your outbound efforts. The key is treating AI like a partner—training it carefully, measuring its output, and integrating it into your existing sales rhythm.
Done right, it turns the slow, manual process of crafting personalised openers into a predictable, scalable engine for better prospect engagement.
