I am slightly confused on how first and last touch channel visits are calculated. My original thought was that when you first reach the site (more than 14 days since last visit), you receive a first touch channel visit and last touch channel visit. And then you continue to get last touch visits if you come back to the site in the allotted time. I am starting to think this is not the case because first touch channel visits are higher than last touch channel visits in my marketing channel report. Could someone please explain why this is? Thanks in advance!
Brent Dykes has a great blog explanation post on first and last touch. However the critical point is both first touch and last touch visits increment over time with subsequent return visits (within the expiration window). So first touch channels visits are likely to be higher in the case of multiple visits as the original first touch channel cannot be overwritten unlike last touch.
From a first-touch perspective, Marketing Channels relies on the visitor engagement expiration, which is a setting you can configure in the Marketing Channel settings. You can configure the engagement window for different lengths of time up to never expire (default is 30 days). Visit engagement expiration operates differently because it will reset and extend the time window if someone returns before the expiration window has closed. I’ll use the following example to illustrate this key difference.
If you captured a channel value in an eVar with an original value setting (first-touch) and choose a month expiration, you may expect to see a similar value in the corresponding first-touch Marketing Channels report. However, when the same visitor returns to the site after 20 days, the eVar value will still expire after 30 days from the original visit. However, with Marketing Channels, the window for 30 days of inactivity resets on the 20th day, and it expands the time window for an additional 30 days from this last touch. If the visitor kept coming back, the first-touch Marketing Channels report would capture more interactions than the original value eVar would.
From a last-touch perspective, the other channel reports such as your traffic sources reports don’t provide a holistic, all-inclusive view like your Marketing Channels reports do. In addition, the specificity that can be achieved through the marketing channel rules as well as the ability to override allocations for various channels will create minor or major differences in the last-touch numbers. In other channel-related reports, various traffic sources will receive more credit for success simply because they aren’t competing with as many other channels. When you have 10 channels in your Marketing Channels reports and only six in your campaigns report, success will not be divided up the same way across channels.