Currently on per-domain uniques, fresh sessions computation named offset counts fingerprinted sessions having made:
- 1 request with no cookies set (nocookie IS NOT NULL)
- 0 request with some cookies set (nocookie IS NULL).
This way of computing the offset undercounts the fresh sessions.
While making sure we count only devices having made 1 request with no cookies set (nocookie IS NOT NULL) is correct, restricting the number by counting only devices having made 0 other request prevents counting devices whose "fresh" session includes more than 1 hit, about 10% of the offset.
Move to production:
- Add a row in documentation about the change in this page