Paid Social Attribution Tracking in 2026
Pixel-only attribution is no longer reliable. Modern attribution combines server-side event tracking, platform modeled conversions, and periodic incrementality tests to give you a defensible read on what each channel actually delivers.
Server-Side Conversions API
Send conversion events from your server using the Meta Conversions API and the TikTok Events API. Server-side events bypass browser blockers, recover lost iOS attribution, and improve match rates by 20 to 40 percent across most accounts.
First-Party Identifiers Where Allowed
Pass hashed email, phone number, and external ID with every event. Higher first-party identifier coverage directly raises match rates and unlocks better optimization.
Modeled Conversions Are Your Floor, Not Your Truth
Treat platform-reported conversions as a directional floor. They are inflated by view-through windows and cross-attribution. Use them to allocate within a channel but not to compare across channels.
Incrementality as the Source of Truth
Run quarterly geo holdout or matched-market tests to measure true incrementality of each channel. Most teams find paid social incrementality is 30 to 60 percent of platform-reported conversions, with the gap closing as first-party data improves.
Frequently Asked Questions
Yes for client-side fallback. Pair it with server-side tracking for the strongest match rate.
Quarterly is the floor. Monthly for accounts above significant spend thresholds.
Above 70 percent for Meta CAPI is strong. Below 50 percent suggests missing first-party identifiers.
No. Last-click systematically over-credits search and under-credits social. Use blended models or MMM.
MMM is increasingly viable for accounts spending several million per year and provides the cleanest cross-channel signal.