6. Analytics

Traffic has started, signups appear, every graph moved this week. None of that tells you whether anything is growing, and none of it tells you which channel sent the people.

Start with where the user actually came from, even though it sits second here. Attribution is the one thing on this route you cannot reconstruct later. Every day you postpone it adds another day of arrivals nobody can place.

The reading itself lives on the numbers worth reading weekly, and the list there is short on purpose: impressions, clicks, index share, signups, activation, repeat use. Each number answers something the others cannot. That is the only reason it is on the list.

What an event row has to carry sits underneath attribution and underneath the weekly numbers. It is seven fields. You write them at insert time, because a field you never wrote is missing for the whole period, and no join afterwards brings it back.