- Second to last campaign, search, or ad
- Last campaign, search, or ad
- Equal credit along the conversion touchpoints
- First campaign, search, or ad
The Multi-Channel Funnels reports are generated from conversion paths, the sequences of interactions (i.e., clicks/referrals from channels) that led up to each conversion and transaction. In the reports, channels are credited according to the roles they play in conversions—how often they assisted and/or completed sales and conversions. Conversion path data include interactions with virtually all digital channels.
Learn more here: https://support.google.com/analytics/answer/1033863