Visits in Marketing channel v/s evar containing Query parameters

What is the expiry of each item set to?

eVars have a default expiry of Visit, Marketing Channels have a default expiry of 30 Days.

Since Marketing Channels have a lot more logic to them (i.e. there are some Marketing Channels that do not override previously set Channels - at least in the default setup) this can be a harder concept to understand for people just starting out.

 In general "Direct" Marketing Channels will not override previously set channels.

So let's look at a scenario:

• Visit 1 - Direct
  • Marketing Channel is Direct - this will remain for 30 days or until over written
  • eVar (not having any query parameters) will be unspecified and last for the Visit
• Visit 2 - Paid Search
  • Marketing Channel will be overwritten with Paid Search - this will remain for 30 days or until over written
  • eVar (having Paid Search query parameters) will be set to paid search campaign and last for the Visit
• Visit 3 - Email
  • Marketing Channel will be overwritten with Email - this will remain for 30 days or until over written
  • eVar (having Emails query parameters) will be set to email campaign and last for the Visit
• Visit 4 - Direct
  • Marketing Channel will continue to be "Email"... there are no parameters, but Direct (under default behaviour) will not overwrite a specific campaign
  • eVar (not having any query parameters) will be unspecified and last for the Visit

Therefore, in the above scenario, Visit 4 in your Marketing Channel will be "Email", but in your eVar it will not be associated to anything.