Doubling charity:water's media investment while cutting cost per monthly donor 25%

Challenge

charity:water funds clean water projects around the world, and its monthly giving program, The Spring, is the leading engine of its long-term revenue and its 100% model, where every dollar from public donors goes directly to water projects. A monthly donor is worth many times more than a one-time gift, yet paid acquisition was not yet optimized to capture those more valuable donors.

Reporting leaned on last-click and in-platform data, which over-credited campaigns like branded search, even though charity:water already dominates its own search results organically, and under-credited channels like Connected TV (CTV). The team needed to scale spend meaningfully, move budget to media that created truly incremental new donors, and steer acquisition toward monthly "Spring" donors, all while keeping unit economics intact.

Solution

Tunomatic directly managed charity:water's agencies and managed-service partners, and worked alongside the analytics and growth product teams to:

• Rebalance the media mix across paid social, paid search, and CTV using both bottoms-up channel reporting and blended attribution frameworks, including LTV:CAC reporting and campaign-level incrementality multipliers.
• Improve conversion signal engineering for Meta and Google campaigns with the agency to prioritize monthly donor subscriptions, and consolidate campaigns to strengthen algorithm performance, scaling Meta spend about 9x at peak while staying within donor acquisition cost goals.
• Cut branded search spend’s share of the media mix by 24%, since charity:water already leads its own results page, and move that budget into more incremental, demand-generating video campaigns across paid social and other digital video channels.
• Raise creative velocity with channel-specific creative testing.
• Focus CTV buying on higher-disposable-income audiences, which delivered stronger LTV:CAC despite higher media CPMs.
• Execute a World Cup campaign across CTV and paid social, including a flighted World Cup streaming TV buy and soccer-themed creative.
• Pressure-test large sponsorship and partnership opportunities against expected donor return, steering budget away from deals that couldn't clear the bar.
• Run landing page experiments to lift conversion rates and overall LTV generation.

Results