The W3C’s proposed “Attribution Level 1” browser standard deserves far more scrutiny from the advertising and measurement community than it has so far received.
The real risk isn’t in running robust tests; it’s in wasting money or cutting high-performing channels based on misleading conclusions from bad measurement.
Randomized controlled trials are the best source of evidence of cause-and-effect relationships, including advertising’s impact on sales. Imagine the potential for conducting geo experiments using ZIP codes instead of DMAs.
