Measuring the effectiveness of online search ads on blood donor recruitment and donation.

Background: Acutely highlighted during the COVID-19 pandemic, the tenuousness of the blood supply continues to be a lynchpin of the most important medical procedures. Online advertisements have become a mainstay in donor recruitment. We set out to determine the effectiveness of online search ads and variations thereof on blood donations with an emphasis on first-time donors.

Study Design And Methods: From September 01, 2022 through March 31, 2023, we performed a campaign comparison experiment through a major search-ads platform with two distinct messages: one altruistic ("Altruistic") and one with a prospect of rewards ("Promotion"). We developed a method to track donation outcomes and associated them with impressions, click-throughs, and conversions. We compared the performance of the Altruistic and Promotion arms to a control group that was not associated with any search-ads ("Baseline").

Results: Analyzing 34,157 donations during the study period, the Promotion group, and not Altruistic, had a significant difference of first-time donors over Baseline (24% vs. 12%, p = 7e-6). We analyzed 49,305 appointments and discovered that appointments made from the Altruistic arm resulted in a significantly higher percentage of donations when compared to Baseline (57% vs. 53%, p = .009); however, the Promotion group had a higher percentage of donations from first-time donors when compared to Baseline (12% vs. 8%, p = .006).

Conclusion: We developed a method for determining the effectiveness of online search ads on donation outcomes. Rewards/promotions messaging was most effective at recruiting first-time donors. Our methodology is generalizable to different blood centers to explore messaging effectiveness among their unique communities.