Confirm Matomo Attribution and whether campaigns take precedence over other channels

[mattab]

Context: Matomo should be using the Last Non-Direct Click attribution model by default and other attribution models available in Multi Channel Report.

As discussed in https://github.com/matomo-org/matomo/pull/20442#issuecomment-1475553091 this may be Matomo's behavior:

• When the visitor was visiting the page with campaign parameters in a previous visit,
• and then might visit via a search engine
• then a goal conversion would be attributed to the original campaign

Problem: Matomo may put priority towards the Campaign stored in the cookie VS other channel.

Steps:

• Confirm the above is the behavior in Matomo and that we have a problem
• Then make a decision whether to keep the attribution as is (and update the documentation instead), or whether to change attribution to match the industry standard Last Non-Direct Click
• Then implement the change

[bx80]

The discussion on #20336 may also provide useful context

[matt825]

Hi @mattab - may I pose a couple of questions related to this: (1) does this issue also pertain to eCommerce Order as well as goals. (2) should this logic apply to all reports that feature Orders and/ or goals

Background: I have data which suggests that different reports within Matomo could be using differing attribution methods. Using eCommerce Orders, I have a figure for orders associated with Campaigns in the Channel Types report which appears to be last non-direct touch, but when drilling into Campaign-Medium (which should show its consituent parts), the figure is a lot lower AND this doesnt correspond with data in the multi-attribution reports.