Understanding Why Google, Meta, and Microsoft Report Different Conversion Counts
TLDR
Ad platforms report inflated conversion numbers not because they're lying, but because they use different attribution windows, engagement definitions, and modeling methodologies—and understanding those differences is critical to using the data correctly.
Search Engine Land explains the structural reasons why Google Ads, Meta, and Microsoft each report wildly different conversion numbers for the same time period. The discrepancies stem from attribution windows (Meta uses 7 days, Google up to 90), differing engagement definitions, view-through conversions especially on YouTube, platform-specific attribution models, and modeled conversions filled in after privacy changes. Rather than treating platform numbers as accounting truth, the article advises using them for optimization—and ensuring all platforms trend in the same direction as a practical indicator that marketing is actually working.