Learn
How the plumbing works. Written from doing the thing, not from reading about it — every guide carries a screenshot, a dataset, a test result or a worked example.
- A hashed phone number is a phone number with an extra step We hashed all 6.4 billion possible US and Canadian phone numbers on one cloud VM in under six minutes. Why a hashed contact list is still personal data.
- Your 90-day click window rests on a cookie that may last 7 LinkedIn credits a click for 90 days but keeps its click cookie for 30. Safari deletes script-set cookies after 7 days. Five platforms' windows and cookies.
- Switching ad trackers? Test what it sends back to each ad platform Eight ad platforms each want their own click ID field, dedup key and deadline, and they hash one email in different ways. What to test in a tracker trial.
- Primary demand advertising also sells your competitors' product Primary demand ads grow a whole category, so every seller gains. In the US, 21 federal checkoff boards buy them and measure the return without clicks.
- Your postback URL returned 200. The conversion can still be lost We sent 22 test postbacks and 12 lost or changed data, often behind a 200 OK: unreplaced macros, raw + and # signs, redirects. How to test first.
- The most visited US websites, and what AI does to the count Four rankings, four rulers. One counts DNS lookups, one hides the adult sites, and none sees an answer read inside an AI assistant.
- Attribution is two jobs: analytics and the ad platform An analytics tool attributes to report across channels. An ad platform attributes to credit its own ads. Sending a conversion server-side does neither job.
- Three tools say "last click", each means a different click Google Ads, GA4 and LinkedIn all offer a last-click or last-touch model. Each credits a different touch, so one sale gets three different answers.
- Two kinds of click ID, and why they never swap Ad platforms and tracking platforms each create their own click ID. Each one only matches in the system that made it, so the wrong one attributes nothing.
- LinkedIn counts a view for 90 days. Google counts 1 day Default view-through windows run from 1 day to 90 days across six ad platforms. Add their conversion counts together and you add unlike things.
- Why your ad platform rewrites past numbers Ad platforms write conversions backward onto the click date, so past days keep changing for as long as the attribution window stays open.