Is Marketo deleting information in Salesforce via list uploads?

[Anonymous]

My sales team is saying that call histories are missing in Salesforce. Could this be a result of uplaoding lists? I know that Marketo overwrites Salesforce; however, to prevent this, I only upload lists with first name, last name & email address. Could the uploads be affecting other portions of data? If so, how can this be prevented?

[Josh_Hill13]

Kate,

No, Marketo should not be deleting tasks, and certainly would not do this via a list import. Marketo can only create Tasks.

Where are you keeping Call Histories? Salespeople should do this ONLY in Tasks. I bet they are using the Description field, which is the Person Notes field in Marketo. This can be overwritten by Marketo or other methods.