I have a number of leads in my Marketo which sync through to my salesforce and have the standard bidirectional sync.
However I have another 30,000 leads which were input straight into Salesforce, and therefore are not in Marketo. I want to mass sync these to Marketo, and was wondering if anyone new best practice?
Do I just download and add them via CSV? Or is there a more efficient method?
They should sync to Marketo automatically unless they are blocked for some reason.
If you post them back to Marketo via List Upload, then you will create dupes.