How I Achieved a 96% CAC Reduction, 75% Retention, and 6K+ Sign-ups Using TikTok Spark Ads

When tasked with growing Goodcall, a platform designed to simplify the scholarship search process, I faced a significant challenge: how to efficiently scale user acquisition while keeping costs low and improving retention. The answer came in the form of TikTok Spark Ads. Through careful planning and a content-driven approach, I was able to reduce customer acquisition costs (CAC) by an impressive 96%, retain 75% of new users, and generate over 6,000 new sign-ups.

Here’s how I did it.

1. The Problem: High Acquisition Costs and Engagement Issues

Goodcall’s service offers great value to students and families, but like many growing companies, we struggled with high acquisition costs on platforms like Google and Facebook. Additionally, while we were bringing in new users, keeping them engaged long-term was proving difficult. With a limited budget, I needed to find a more cost-effective way to not only acquire users but retain them as well.

2. Why I Chose TikTok Spark Ads

TikTok was a natural choice for reaching our core audience—students and young adults—because of its enormous popularity among Gen Z. Spark Ads stood out because they allow brands to amplify existing organic posts. These ads blend seamlessly with regular TikTok content, making them feel less like traditional advertising.

My goals were clear:

• Cut acquisition costs by moving away from more expensive platforms.
• Increase user retention by delivering content that users connected with.
• Drive new sign-ups by creating authentic, engaging campaigns that resonated with our audience.

TikTok’s user base and Spark Ads’ organic feel provided the perfect opportunity to achieve these goals.
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3. How I Built the Campaign: Strategy and Execution

To get the best results, I developed a three-part strategy:

A. Boosting User-Generated Content (UGC)

I knew that TikTok thrives on authenticity. Instead of creating polished, professional ads, I focused on amplifying content made by actual users of Goodcall. We promoted videos from students who had successfully used our platform to find scholarships. These authentic testimonials spoke directly to our audience, showing real success stories rather than corporate marketing.

• Why this worked: Real stories from real users are far more relatable than traditional ads. People trust other people, and TikTok is all about connecting through shared experiences.

B. Collaborating with Influencers

I partnered with influencers who were popular among students, especially those in the education and study spaces. These influencers created content showing how Goodcall could help students find and apply for scholarships. Their genuine support for our platform lent credibility to the campaign and allowed us to tap into their engaged followers.

• The impact: Influencers already have a loyal audience. By having them share their experiences with Goodcall, we could reach students more effectively than through standard ads.

C. Targeted Advertising

Using TikTok’s precise targeting features, I was able to reach students who were actively searching for scholarships or interested in education-related content. I also utilized retargeting strategies to follow up with users who had interacted with our content but hadn’t yet signed up. This ensured we maximized the impact of every interaction.

• Precision matters: Targeting the right people, instead of casting a wide net, allowed us to keep acquisition costs low and drive higher engagement from users who were already interested in what we offered.

4. The Results: A Game-Changing Campaign

The results of this TikTok Spark Ads campaign far surpassed our expectations:

• 96% Decrease in Customer Acquisition Costs: By shifting to TikTok and focusing on authentic content, I was able to slash our CAC by an incredible 96%. This freed up budget for other growth initiatives and allowed us to scale efficiently.
• 75% Retention Rate: User retention was just as important as acquisition, and I’m proud to say that 75% of the new users we acquired stuck with the platform. The authenticity of our content kept them engaged beyond their initial sign-up.
• 6,000+ New Sign-ups: The campaign resulted in more than 6,000 new user sign-ups, significantly boosting our user base and overall growth. TikTok’s viral nature, combined with influencer collaborations, played a major role in achieving these numbers.

"Our team found a product market fit with our AI phone assistant for small businesses and needed a scalable way to grow. We ran experiments across a number of marketing platforms and found TikTok to be by far the most effective and efficient at finding our audience. The result is 34% sustained month over month growth with plenty of opportunity to optimize." -Bob Summers, CEO and Founder at Goodcall

5. Why TikTok Spark Ads Worked for Us

The beauty of Spark Ads is that they allow your content to blend naturally with what users are already engaging with. Here’s why this approach was so effective for Goodcall:

• Authenticity is Key: TikTok users value real, relatable content over polished, scripted ads. By promoting organic user-generated content, we built trust and created a more meaningful connection with potential users.
• In-Feed Integration: Spark Ads appear in the same format as regular TikTok videos, making them less disruptive. Users often engage with them just as they would with any other content on the platform, leading to higher levels of interaction.
• Viral Potential: TikTok’s algorithm promotes content based on engagement, so the more people interacted with our Spark Ads, the further they spread, giving us significant organic reach on top of the paid boost.

6. Key Takeaways from the Campaign

This campaign taught me several important lessons that will shape future growth strategies:

• Be Authentic: TikTok users can spot inauthentic content from a mile away. Whether through influencers or user-generated content, the more genuine the message, the better the response.
• Focus on Engagement, Not Just Impressions: It’s not enough for people to see your ad—they need to engage with it. TikTok’s engagement-first model works in favor of brands that focus on creating interactive, relatable content.
• Retention Should Be a Priority: Acquiring new users is only half the battle. Creating content that keeps them engaged after their initial sign-up is crucial for long-term success. For us, the 75% retention rate was proof that good content fosters loyalty.

Scaling TikTok’s Success

With the success of this campaign, I plan to continue using TikTok Spark Ads as a key growth tool. Here’s what I’m focusing on next:

• Expanding Influencer Partnerships: We’ll collaborate with more influencers across a variety of niches to reach new audience segments.
• Exploring New Ad Formats: In addition to Spark Ads, I’ll test other TikTok ad formats to see how they perform with our audience, particularly In-Feed Ads and TopView Ads.
• Doubling Down on Retargeting: We’ve seen great results from retargeting users who have engaged with our content, so I plan to further refine this approach to maximize conversions.