Import tradeshow list without creating duplicates

this is strange because Marketo doesn't allow email address duplicates when you load a list...

Exactly what I thought - but it did.  If there was a contact record, it added it as a lead so now I'm stuck converting about 600+ leads and matching with the existing contact record.  How do I avoid this going forward?

I have had that experience as well where Mkto does not de-dupe when there is the same email address. Not sure why that is the case, but it has happened. One way to check without importing is just to copy and paste all of the email addresses into a Smart List. If there are any duplicates, you can export the list and do a v-lookup within your .csv spreadsheet to remove the duplicates. Then, you can add the Leads that do exist (from the Smart List) to a Static List in case you want to update them in any way. Keeps things cleaner.

A VERY manual process, but worth it for big list imports in my opinion.

I'm still curious as to what to do about this.  I have yet another list to import but dont want them co-mingled with contacts - any suggestions?  Also, is there a way to import a list and NOT have it put into Salesforce?

Anyone?  Marketo folks?

Do all of the records have email addresses? One way is to copy all of the email addresses into a smart list and then run it to see which ones exist. Once you find them, you can export the list and do a Vlookup to find them and remove them from the list you are about to import. 

The email address should work though. Can you send a screen shot of what Step 1 of your import looks like?

And yes, you always have the capability to keep records in Mkto without syncing to SFDC. Just make sure you don't have any system wide rules that will sync them. If not, then skip that step in your processing of the list.