Hi Josh, Thanks for adding your warning about backing up data and being prepared to lose SFDC data! It caused me to search further and find this important instruction from Michael Langellotti's about exactly how to prepare for this. At the risk of plagiarizing, I couldn't say it any better than Michael! **VERY Important BEFORE creating new SFDC fields to sync with existing MKTO fields: This comment from: Michael Langellotti Oct 11, 2016 2:03 PM (in response to f76223ef9dd6d6ff05baf7e168456b8cb6991853)Adding Marketo Fields to Salesforce "Yes, you create the fields in SFDC and then you create a ticket with Support to have them manually map the custom fields together for you. **VERY IMPORTANT: whenever you do this, you need to block field updates from SFDC sync in the admin section in field management. Why? Since SFDC is always considered the source of truth, and since the new SFDC fields contain all NULL values, it will start Nulling out your Marketo data. To prevent this from happening, you need to upload all the field data to SFDC first, and then you can re-enable the SFDC sync. So steps below 1. Block Salesforce sync from Marketo fields 2. Create ticket asking Tech support to map fields 3. Upload data into SFDC fields from Marketo 4. Re-enable Salesforce sync Goodluck! -Mike"
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