Attribution models and channel rules

Each visit (session) is a touchpoint. A conversion looks back over the visitor's touchpoints inside the lookback window:

• First touch: all credit to the earliest touch. Last touch: all to the latest.
• Last non-direct: the latest touch that wasn't Direct (falls back to Direct if that's all there is).
• Linear: equal shares. Position-based: 40% first, 40% last, 20% shared by the middle (50/50 with two touches).

Conversions with no touch in the window count as Direct. Revenue is split in whole cents so totals always add up.

Channels come from an ordered list of rules on Channels (e.g. “utm_medium is one of cpc, ppc → Paid search”). Edit, reorder or reset them; reports re-classify past visits immediately because we store the raw tags. A new session starts after 30 minutes of inactivity or when a visit arrives with different campaign tags or referrer.