Do Marketo Lists Automatically Dedupe?

[Anonymous]

I am almost done setting up a new nurture stream and at the start we want to have it where to get added to the stream you have to be manually added to a list.  Inlight of issues I have had with 1 lead being added to a list twice during the same import.

I want to know if a lead already exists on a list and it is part of another list I am trying to add to it will it be added twice?  So if I import a spreadsheet to that list or have a smart list that I manually add to the list, will this result in that lead being part of the Nurture List twice?

Thanks,

Patrick

[Anonymous]

As long as the email addresses are the same, Marketo will recognize that it is the same lead and only add it once.

This is assuming that your qualificiation rule is set at "Each lead can run through the flow once."

[Anonymous]

Thomas,

If Marketo recognizes that a lead is already part of a list and doesn't add it shouldn't I then not need to have it so "Each lead can run through the flow once?"

[Anonymous]

That is correct if you are running a batch campaign, but if you are running a trigger campaign this will prevent the lead from running through the flow more than once.

[Anonymous]

While I understand that, I guess I am still unsure if Marketo will actually prevent multiple leads from being added to a list.  If my trigger is "Is added to List: Nurture" and a lead is already part of this list, the next time I go to add people to that list can a lead be added again?

If I had the rule "Each Lead Can Run Through The Flow Everytime" will Marketo recognize that the same lead alread exists on the Nurture list and not add it? or will it add it again and trigger the Nurture Campaign?

[Anonymous · Accepted solution]

The same lead can only exist once in a list. If you have duplicates in your system, meaning that technically they are different leads, they can both be in the same list, but Marketo should only email the address once in a flow.

If you were to try adding this lead to the list a second time, I believe the activity on that record would show something like "Action skipped: already member of list"

If you have the rule "Each Lead Can Run Through The Flow Everytime", everytime you batch the campaign, all leads on the list will enter the flow even if they have already received it. Marketo will still recognize that the lead is alreay on this list in this scenario as well.

[Anonymous]

Ok, that is what I was looking for.  Since being added to the list trigger the nurture and alead can only be added to the list once, then I don't have to worry about a lead being added again later and running through the same flow.

[Jep_Castelein2]

Actually, you do have to worry about that. If there are duplicates in your list, it will give an "add to list" event twice, resulting in the lead being entered in the trigger nurture campaign twice. Therefore, go to the "schedule" tab in your campaign and select "run once" to avoid any issues. 

If I take a step back: you may want to turn this campaign into a batch campaign: it will perform better since all emails will be sent in one go, instead of being sent one-by-one. This difference is not very noticable if we're talking about a couple of thousand emails, but for larger lists batch performance will be much better. 

Best, 
Jep