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How We Exceeded Waitr’s User Re-engagement CPA KPI

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Campaign Goals worked with our long-time partner, digital marketing agency Pipar\TBWA, to re-engage users of the Waitr app. These users had installed the app but never converted to paying customers by purchasing Waitr’s food delivery service.

Our ultimate goal was to bring users, living in specific US cities where the service is available, back to make their first purchase and become engaged, recurring customers. has been a great partner and has proven to be a valuable addition to our marketing strategy.

Cole Mark, Director of Marketing @ Waitr

Results at a Glance:

CPA 19% lower

than the KPI

Most users re-engaged by

made multiple purchases and became recurring customers


Our in-house DSP is integrated with all the major SSP platforms and is constantly processing more than 1.5M QPS of in-app inventory. For each auction, we apply user-level targeting via our machine-learning algorithms to run effective UA and retargeting campaigns. Our algorithms are based on real-time request data and aggregated data from our DMP.

With Dynamic Audiences — our proprietary segmentation engine available to our clients at no extra cost, eliminating the need to use a third-party tool — we quickly defined user segments based on their in-app behavior and current stage in the Waitr funnel. By analyzing unattributed data provided by the client as well as insights from past campaigns, we generated a segment of users in the later stages of the funnel who hadn’t completed it. This allowed us to drive a high volume of first purchases. 

Shortly after gathering a representative number of conversions (re-engagements and re-installs), we were able to leverage our attributed data to narrow down our target audience and focus on users with a higher probability of becoming loyal, returning customers. This allowed us to consistently reduce the CPA and exceed the KPI by a significant margin.

Campaign Results

User Engagement CPA KPI

Once we had collected enough sample data for our machine learning models to classify between 1) users who were likely to convert by making a first purchase and 2) non-converting users who would not make a purchase, the bottom line KPI—the CPA—began to steadily decrease. The original segmentation already produced results well below the KPI, and the additional layer of optimization from classification allowed an even steeper decrease. 

Two different CPA KPIs were provided – one for the initial exploration period of one month, and another, 25% more aggressive, for the following period when enough data was accumulated.

Within the first weeks of running the campaign, we were able to exceed the exploration KPI, generating CPA 19% lower than the target. During the second month of running the campaigns, we were able to exceed the aggressive KPI, generating conversions at 19% lower than the target CPA.


Bid Shading

An additional layer of optimization was required due to the prominence of first-price auctions, an auction model recently adopted by most SSPs. In first-price auctions, the highest bidder wins the impression for the exact price they bid. This is opposed to second-price auctions, where the first bidder still wins, but the price per bid is determined by the second-highest bid (+$0.01). This increases the risk of significantly overpaying for impressions.

Bid shading is a technique of predicting the market price of an auction and allowing DSPs, which can forecast bid price, to avoid overpaying while maintaining scale. Processing 1.5M requests per second,’s DSP has both machine learning models and enough data to efficiently predict the lowest price to win the impression. 

CTR Trend 

Due to careful, personalized creative selection, we immediately saw high CTR that continued to improve MoM as scale increased. Shortly after the campaign started, we analyzed the data to predict best-performing hours where the budget should be spent and set up proper time-based pacing.

About Waitr

Founded in 2013 and based in Lafayette, Louisiana, Waitr is a leader in the on-demand food ordering and delivery market. Waitr, along with its acquired food delivery companies Bite Squad and Delivery Dudes, connects local restaurants to hungry diners in underserved US markets. Together, they make it convenient to discover, order, and receive great food from local restaurants and national chains.

“ quickly proved itself to be an important partner to us as we were able to scale performance efficiently, their no nonsense approach is refreshing and customer service is excellent. We’re happy to include them in our marketing stack.”

Haukur Jarl, Performance Marketing Director @ Pipar\TBWA

About Pipar\TBWA

Pipar\TBWA has offices in Reykjavík, Iceland and Oslo, Norway and is a part of TBWA which was named one of the World’s Most Innovative Companies by Fast Company in 2021, 2020 and 2019, is Adweek’s 2021 Global Agency of the Year and comprises over 300 agencies worldwide. As a full-service ad agency Pipar\TBWA helps companies with their digital transformation and is one of Europe’s leading full-service digital marketing agencies, working with all facets of the online world.

“Cole from Waitr and Haukur from Pipar\TBWA are great reliable partners. They could quickly understand the importance of providing data which helped our machine learning algorithm optimize and improve the performance. I truly value the level of transparency we reached with the client – this definitely contributed to the overall campaign success.”

Gal Koragi, Head of Operations @

About is a mobile-first DSP operating worldwide. Using our proprietary bidder and machine-learning algorithms, we offer transparent, performance-driven, highly-targeted UA and retargeting solutions at scale with access to over 1.5 Million ad auctions per second. We are trusted by CoinDCX, Games24x7, Ubisoft, Tilting point and many others. strives to be more than just a vendor for its partners, but a partner that helps generate actual value, growth, and broad marketing insights that can be used across channels.

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