It is configurable. You can select any attribution against any metric on the fly in the new Analysis workspace when you build out a project and add metrics to the canvas. Note all these are rules-based models. There are more options if you want to apply predictive attribution.
There are main two reports related to traffic sources, so the answer depends on which report you’re looking at:
Campaign Report (s.campaign)
The campaign tracking in Adobe Analytics has been around forever, and captures data for incoming traffic sources where it is possible to append a campaign ID to the incoming link. This means that the old default campaign tracking did not contain data about direct, referral, or organic search traffic. Those were in separate reports.
s.campaign is really just an eVar, which means it has all the same options for configurations as any other eVar. Allocation options include the following:
1.Original (First) — all credit is given the first value
2.Most Recent (Last) — all credit is given to the last value (this is the default setting)
3.Linear (Shared) — credit is shared equally across all value.
Additionally, it is possible to use participation metrics. This is not a setting on s.campaign, but a type of metric. Participation metrics give 100% credit to all values.
Marketing Channel Reports
A few years back, Adobe realized that it was not yielding an accurate and holistic view of traffic sources to have separate reports for campaigns, referrers, direct, and organic search. So they launched Marketing Channels, which allow you to create customized Marketing Channel categories and to write rule-based logic to assign incoming traffic to each of those channels to provide a more unified view.
There is no allocation setting for the Marketing Channel reports, by default it gives you both First-Touch and Last-Touch concurrently in the interface so you can compare them. There is no “shared” option.