A soft credit is a credit for a donation that a contact or donor did not actually make, but may have somehow influenced. A common example is similar to Peer2Peer fundraising. If Jane is running for charity, and John supports her by donating $50, the donation is made under John's name, but the soft credit for $50 goes to Jane because she influenced, but did not literally donate, the money.
ProntoDI allows you to specify Soft Credit contact on upload of the Opportunities. You can do this either via the Upload Page, or in the CSV file.
Set Soft Credit on Upload
The easiest way to attribute soft credit is to set the Contact on the Donation Upload Tab.
Thus all donations uploaded will have the selected Contact as the "influencer" Contact role.
Multiple Soft Credits in CSV File
If you have multiple contacts who you would like to assign soft credits to, you can do this within your CSV file. Have a column for Soft Credit First Name, Soft Credit Last Name, (Optional Soft Credit Email or Salesforce Contact ID) and mark the appropriate as Unique Identifiers when you create your mapping template in ProntoDI.
Make sure you remember to set the Contact Role to "Influence" on the Donation Upload page
The Result in Salesforce is that you will see the soft credit contact added to the Contact Roles related list on the Opportunity (Donation). The Soft Credit numbers on the Contact will be updated overnight by batch.