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Unlocking the Voice of the Customer: Using LLMs to Elevate Your Marketing with Sales Call Transcripts

January 28, 2025

The better you understand your customers, the more effectively you can reach them. Yet, achieving this level of understanding is no small feat. Customer surveys, focus groups, and analytics provide invaluable insights—but often, the richest source of understanding comes from the conversations your sales team has every day with prospective customers. These conversations are full of real questions, objections, goals, and desires, making them a goldmine for marketers looking to craft resonant messaging. Leveraging large language models (LLMs) like ChatGPT, Gemini, or Claude, to analyze sales call transcripts is an emerging strategy that unlocks the true voice of the customer.

In this post, we’ll walk through how to use LLMs to “learn” from sales call transcripts, understand the voice of the customer (VoC), and apply that voice across your marketing campaigns.

Why Use Sales Call Transcripts to Inform Marketing?

Sales calls are a direct window into the minds of your customers. They reveal:

  • Customer pain points: Learn what challenges they face and how they articulate them.
  • Language and tone: Identify how customers describe your product, their needs, and their goals.
  • Objections and questions: Understand what might hold customers back from making a purchase.
  • Motivators: Pinpoint what customers value most when making decisions.

By analyzing these insights, you can refine your messaging to resonate with customers at every stage of their journey. The challenge is sifting through hours of recordings and pages of transcripts to identify patterns and themes. That’s where LLMs come in.

Step 1: Gather Your Sales Call Transcripts

To start, you’ll need transcripts from sales calls. If your organization already uses tools like Gong, Chorus, or Google Meet (with transcription features enabled), you likely have these files at your fingertips. Here’s how to prepare them for analysis:

  1. Export Transcripts: Export sales call transcripts into a readable format like .txt, .docx, or .csv. Most platforms provide this functionality.
  2. Organize by Call Type or Stage: Label transcripts based on the customer segment (e.g. industry or role) and  sales stages (e.g., discovery, demo, closing). This helps you analyze trends across the customer journey.
  3. Anonymize Data: Remove personally identifiable information (PII) from transcripts to ensure compliance with privacy regulations (e.g., GDPR, CCPA).

Step 2: Feed the Transcripts into the LLM

Using an LLM like OpenAI’s GPT-4 (or another tool of your choice), you’ll now process the transcripts to uncover patterns and insights. Use the following prompts to extract actionable insights. “Analyze the following transcripts and create a summary of the top 3 pain points, 3 objections, and 3 motivators customers mentioned. Highlight any recurring phrases or themes.” This will give you a high-level view of your audience’s needs and mindset, which you can then use to inform marketing strategies.

  • For Identifying Pain Points: “Analyze this sales call transcript and identify recurring customer pain points. Summarize them in a list with brief explanations.”
  • For Voice of the Customer Analysis: “Examine this transcript and summarize how the customer describes their challenges, goals, and desired outcomes. What specific phrases or terms do they use?”
  • For Objection Handling Insights: “Identify objections or hesitations mentioned by the customer in this transcript. Suggest ways these objections could be addressed in marketing messaging.”
  • For Tone Analysis: “Describe the tone and language the customer uses in this transcript. Is it formal, casual, technical, emotional, etc.? Summarize with examples.”

Step 3: Apply Insights Across Marketing Channels

Now that you have a clearer picture of your customer’s voice, here’s how to apply it to various channels. Take your existing copy and ask the LLM to adjust the tone to match the voice of the customer. For example, Please rewrite the following [Ad/Email/Landing Page] for [Customer Segment] using the results from step 2. This can be applied to:

  • Paid Ads: Write ad headlines and copy that directly address customer pain points or goals. Use customer-centric phrases uncovered from transcripts, such as “Save time on [task]” or “Get rid of [frustration].”
  • Landing Pages: Create landing page headlines that echo the language customers use to describe their challenges. Include testimonials or case studies addressing objections.
  • Email Campaigns: Personalize emails with pain-point-specific subject lines, such as “Frustrated by [challenge]? Here’s a solution.” In follow-up emails, address objections with data or stories that alleviate concerns.
  • Content Marketing: Publish blog posts or guides tackling common questions or objections (e.g., “How to Solve [Customer Pain Point]”). Create FAQ sections based on actual customer questions.

Step 4: Monitor and Iterate

As you roll out campaigns informed by VoC insights, monitor their performance closely. Track key metrics like click-through rates, conversion rates, and engagement to measure the impact of your new messaging. Then, refine your approach by gathering fresh sales call data and repeating the process.

Pro Tips for Success

Combine LLM Analysis with Human Expertise: While LLMs can surface trends and patterns, human review is crucial for context and nuance. Involve your marketing and sales teams in the analysis process.

Use Multiple Data Sources: To get a 360-degree view, supplement sales call transcripts with other VoC inputs, such as customer surveys, support tickets, or social media comments.

Train the LLM Over Time: If you use custom LLM solutions, train the model on your industry and product to improve accuracy and relevance.

Focus on Actionable Insights: Avoid getting lost in the details. Prioritize insights that can directly impact your messaging and campaign strategies.

Stay Privacy-Compliant: Always anonymize customer data before using it in AI tools and ensure compliance with all relevant privacy regulations.

Conclusion

Using LLMs to analyze sales call transcripts is a powerful way to understand your customers' voices at scale. By capturing how customers speak about their pain points, goals, and objections, you can craft marketing campaigns that truly resonate. This strategy improves messaging, builds trust, shows empathy, and positions your brand as a partner in solving real problems.

So, start gathering sales call transcripts, fire up your favorite LLM, and watch your marketing strategy transform. TYour customer's voice is waiting—you just need to listen.

Wesley MacLaggan

Marin Software
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