Introduce an equivalent to 'Instances' Metric for List Vars

[#1]

It's often very important when undertaking analysis to be able to understand when a value is set rather than propagated forward.

With eVars this is possible using the corresponding "instance" metric for the eVar.

With List Vars I cannot see any way of differentiating between values carried forward and those values actually set within the hit.

Please can you consider introducing a way to differentiate between List Var values that have been 'set' rather than just carried forward?

[note: I think this is similar to the issue often faced with products variable where segmenting a specific product at a the hit level returns all products captured in the hit  i.e. it is currently impossible to isolate something at a 'sub-hit' level]

[#2]

Just so I'm clear, is this a scenario where you'd have to set a custom event to reproduce instances? In other words, would setting a custom event get you what you need here?

[#3]

Thanks Ben, I was considering setting a custom event whenever the list Var is set.

However, this doesn't work because the List Var could contain values which were 'set' on the hit, and values propagated forward from a previous page - I want to be able to isolate the values 'set' in the hit

Does this make sense?

[#4]

Just to give you a bit more context...

The use case I am currently trying to set up for is where we have 4 marketing assets on our homepage (hero banner and three sub panels) which contain different marketing content, each with a internal campaign id.

I'm trying track the impressions using a list var set to full allocation with a 30 day expiry (30 day expiry so we can also track the impression through to a goal completion)

Here is an example of why it doesn't work...

• User visits the homepage on day 1 and sees marketing assets A,B,C & D.  These campaign IDs are set into the list var and a custom event for "impression" is set.
• Day 2 the same user returns and sees marketing assets E, F, G, H.  These campaign IDs are set into the list var and a custom event for "impression" is set.
• If we look at the analytics report across both days, I believe we'll get two impressions for marketing assets A,B,C, & D (even though only one impression occurred) because the values have been propagated forward to the next day and are therefore present when the second impression event gets logged

Marketing Asset     Impressions

A                                2

B                                2

C                                2

D                                2

E                                1

F                                1

G                                1

H                                1

We could work around this by tracking impressions in another list var set to hit expiry but this would mean we couldn't show impressions and goal completion in the same report (or % conversion) and it would eat up another one of our precious list vars!

Hence, it would be really useful to be able isolate when a list var value is 'set'

Hopefully this help illustrate the issue