Attribution used to be whatever the analytics vendor said it was. Once the event stream lands in the warehouse, the model becomes a query — and a query is something a data team can argue with, version and test.
That shift moves the hard part from tooling to definitions. Which touchpoints count, how long the lookback window runs, and whether a self-serve signup inherits credit from a webinar six weeks earlier are product decisions, not vendor defaults.
The cost is latency and maintenance: a warehouse-native model recomputes on a schedule rather than on every pageview, and somebody owns the SQL. Most teams find the trade worthwhile the first time finance and marketing agree on a number.