Enhancing ROAS for Spirit Airlines Through Custom Bidding


Cramer-Krasselt (C-K) is one of the largest independent agencies. More than integrated, it's totally interconnected and offers an ever-expanding range of disciplines from strategic branding to performance marketing and more. With a mission to Make Friends, Not Ads®, C-K has built a reputation for changing perceptions and behaviors that significantly move the purchase needle.


C-K's client, Spirit Airlines, has delivered affordable, high-value journeys for over two decades. Their commitment to value and customer-centric services allows guests to venture further and more often than ever before. Recognizing the opportunity to further enhance its customer reach, Spirit Airlines sought to achieve a higher ROAS on their programmatic media efforts. C-K's challenge was twofold. First, they needed to develop a strategy to effectively reduce Spirit Airlines' CPA at both the advertiser and route levels. However, they needed specific and nuanced Display & Video 360 (DV360) knowledge and technical Python coding expertise to achieve this.

Second, the agency had to contend with the intermittent nature of campaign budgets, which made acquiring adequate data for efficient modeling challenging. The team needed a sustainable solution to help them accurately target specific customer actions, such as booking confirmations, and help them optimize the entire conversion funnel.

To overcome these challenges, C-K sought a durable solution encompassing all display and native channels, aiming to balance technical sophistication and practical application.


Recognizing the need for a sophisticated approach to drive higher ROAS for Spirit Airlines, C-K collaborated with Adswerve to harness the power of DV360. This partnership was instrumental in developing a custom, robust solution utilizing one of DV360’s most sophisticated features, Custom Bidding.

Adswerve partnered with C-K to meet these challenges by adopting:
  • Custom Algorithm: Using DV360's Goal Builder to devise a custom algorithm to drive lower CPAs at the advertiser level
  • A/B Testing: Testing the Custom Bidding IO against a Fixed Bid IO for direct performance comparison.
  • Skill Augmentation: Adswerve's experts in Python and Google Marketing Platform technology helped train, support and advise throughout the entire process.


Leveraging Custom Bidding for Spirit Airlines, C-K produced immediate and significant results. The strategy's success was evident in the dramatic improvement of key performance indicators, including:
  • A 149% increase in conversions
  • A 1.5x increase in ROAS
Future plans include developing a custom script with u-variables for specific route CPA performance and exploring more granular optimization strategies for media purchasing and allocation, ensuring sustained growth and an even higher ROAS for Spirit Airlines.

About Custom Bidding

With DV360’s Custom Bidding feature, you can enhance your campaign's bidding strategy with advanced control and precision, including:
Digital Analytics
Optimizing for Valuable Impressions
Strategically bid on impressions that align closely with your campaign goals.
Testing, Personalization and Optimization
Granular Control
Use weighted values and a variety of optimization tools to target specific conversion events effectively.
Ad and Media Tech
Machine Learning-Enhanced Bidding
Leverage a training phase where the algorithm learns from past campaigns to improve bid scoring and prioritization.
Business Intelligence and Visualization
Two Ways to Get Started
  • Create a Custom Bidding Goal: Optimize impression values using weighted conversions, building a custom algorithm without complex scripting.
  • Write a Custom Bidding Script: Use basic Python knowledge to incorporate first-party data for non-conversion-based goals, like Brand Lift measurements.
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