I have searched far and wide in the documentation but would be great if someone could help me understand (ideally through an example) why the 'marketing channel instances' metric would not be the same as the visits for an individual marketing channel (in my reports, visits > instances for each marketing channel...i am using last touch btw).
If i come via referrer A onto the website, this is registered as 1 instance and 1 visit for the referrer channel. I do not understand why for every visit to the website, an instance will not be counted? i.e. every visit from referrer A should have an instance for referrer A
In what condition would the visit be higher than the instance..in layman terms?
Visits: It is defined as a sequence of consecutive page views without a 30-minute break, or continuous activity for 12 hours. Visits most commonly consist of multiple image requests. However, visitors that bounce can consist of a single page view.
Visits in case of Marketing Channel reports: The number of visits that touched a particular channel. There can only be a single marketing channel attributed to each visit, however last touch visits can match more than one channel during the same session.
Marketing Channel visits higher than site-wide visits: The total visits at the bottom of each report always match. However, it is common for the sum of last touch visits in marketing channel reports to be higher than site-wide visits. For example:
A user arrives to your site via paid search and does not find what they are looking for. They click the Back button.
Going through each of the search results, that same user arrives to your site via a natural search link. They browse around your site and leave again.
This user touched both the Paid Search and Natural Search channel increasing both visit line items. The total visit count however is de-duplicated, as it was still a single visit.
Site-wide visits higher than Marketing Channel visits: This comparison is not possible in reporting. Any visits that do not touch a channel are listed under No Channel Identified, which is a line item in Marketing Channel reporting. If this line item was omitted, site-wide visits could be higher than Marketing Channel visits. Depending on your Marketing channel processing rules, not everybody is required to touch a channel in a visit.
Marketing channel logic is completely custom, so for one organization it might be exceedingly normal to have more visits than marketing channel instances. A common example would be 'direct' or 'internal'. Many organizations do not allow these traffic sources to override an existing channel. So if I come via paid and then 5 days later via direct I would see two visits for paid and one marketing channel instance. The paid channel is persisted into the next visit in that scenario.