Uploading a static list without overwriting current contact

[Anonymous]

Question is essentially stated above. I want to be able to upload a list of individuals that attended one of our events. I want to make sure though that if the person already exists in Marketo though that we are not overwriting their information. How do I upload the list without making a list of current Marketo contacts?

[Grant_Booth]

Kevin,

You'll want to set this up in Admin > Field Management by blocking that field from updates for list imports: Block Updates to a Field - Marketo Docs - Product Docs

Grant

[Anonymous]

Thank you! So I understand that it would block the update and believe I have seen this before. I remember seeing Marketo provide a report of contacts that Marketo tagged as duplicates or that stated ExplicitCompanyUpdateNotAllowed. From what I understand though, this would block them from being added to the list completely. I still want them added to the list and just want Marketo to not make a duplicate of them.

[Grant_Booth]

Hi Kevin,

Unless something is broken (cross your fingers) Marketo should not be making a duplicate - it will dedupe automatically based on the lead's email address. If it's creating duplicates I recommend making sure there aren't any leading or trailing spaces in the email address column of your list (you can use the TRIM() function for that in Excel). TL;DR list imports shouldn't create duplicates.

Blocking the field from updates means that the list import will not overwrite the existing field value during the import - it will just create the record or update it's other fields, and add them to the list. This does not prevent them from being added to the list. Test it out!

Grant

[Anonymous]

Thank you so much! This makes so much sense and helps me understand so much of what I have been seeing. I unfortunately believe I had overwritten some leads and wanted to know if there is a way to revert a list of leads to their prior state?

I am taking over for our fulltime Marketo guy while he is on paternity leave and am afraid I made a mess of things. I am thinking I owe it to him to find a solution to fixing the overwritten leads before he comes back.

[Jason_Raisleger]

How big is the list? One thing you can do is create a smart list with "email address is" and then paste all of the email addresses in the list. Then you can export that list with all fields so that you can go back to it if need be. I do that anytime I make large changes to our person database.

[Grant_Booth]

Hi Kevin, unfortunately...no. Messing up a list import is as painful as it gets. Are you sure it was bad data that you imported? May not be a big deal. If you had a column misalligned or something (i.e. names not matched correctly to email addresses) you can just correct the list and then reimport it to fix it.