Three platforms each claiming conversions independently
Japan is one of the very few markets where three major ad platforms — Google Ads, Yahoo Japan Ads, and Meta — each hold enough audience share to run simultaneously and each generate conversion claims independently. Without a unified attribution model, the same customer journey is credited to whichever platform last touched the user before conversion, and in many cases all three platforms claim partial or full credit for the same conversion event. The combined conversion total across all three platforms routinely exceeds actual conversion volume.