Measurement in a Post-iOS14 World

Attribution is broken. The "Golden Era" of 28-day click attribution in Meta is gone, and it's never coming back. Privacy changes like iOS14 and the impending death of third-party cookies have made traditional tracking unreliable.

The New Measurement Stack

To scale today, you need to move beyond platform-reported ROAS.

1. Marketing Efficiency Ratio (MER): This is your "North Star" metric. It is calculated as (Total Revenue / Total Marketing Spend). It tells you how hard your marketing dollars are working for the business as a whole, regardless of which platform claims the credit.
2. Marketing Mix Modeling (MMM): This is a top-down statistical approach that looks at how spend in different channels correlates with revenue over time. It's essential for understanding the long-term impact of brand awareness and top-of-funnel spend.
3. Post-Purchase Surveys (PPS): Simple but effective. Ask every customer: "How did you first hear about us?" You'll be surprised how often the answer is "TikTok" when Meta is claiming the credit.

Server-Side Tracking

If you aren't using Meta's Conversions API (CAPI) or Google's Server-Side GTM, you are likely missing 20-30% of your data. By sending events directly from your server to the ad platform, you bypass browser-based ad blockers and privacy restrictions.

Stop looking for "perfect" attribution. It doesn't exist. Instead, look for "triangulation"—using multiple data sources to make informed decisions.