Here is additional information about native de-dupe behavior for form submissions to supplement the great article John Mattos wrote about "The Unintended Consequences of Duplicates in Marketo."
During form submissions if the record isn’t cookied and their email address is in Marketo multiple times, Marketo will match with the one which was most recently updated (by last modified date in the “updated” field).
- The data value changes in Marketo will only affect one record if there are duplicates; they will not affect the duplicate records. For example, if a record changes their title, the change will not occur for the duplicate records.
There is one exception to the rule highlighted above. If the unsubscribed (SFDC opt-out) field changes to true, Marketo will automatically unsubscribe all records with a matching email address. Thus, if the SFDC opt-out field changes to true all records with the matching email address will change to true. The data value change will be noted in the Marketo activity log for each of the records.
- Assuming that the Marketo cookie information is included in the form (standard for Marketo landing pages or embedded Marketo forms), the web page visits will now be tracked on the most recently updated record.
- If there are duplicate records in Marketo and one of the records is cookied, the cookied record will be associated to the form fillout regardless if a duplicate record was updated last. Thus, the cookied record in a browser will always be matched/win versus a duplicate record which clicks on a link in an email.
- The form fill-out activity may not be associated to a record which was sent the email directing them to the form fill-out
- Pre-fill and progressive profiling will work when a record is cookied or sent an email
- If a record is not already cookied it will become cookied when they fill out a form or click a link in an email which takes them to a web page which contains the munchkin tracking code
- Any anonymous web activity will appear once the record is cookied