Anyone who manages a Marketo knows they bill based on volume of records in the system so there’s a constant battle to keep the number of records under the billing cap while still keeping any potential leads available for marketing. Way back in the day I used to just export the inactive records to csv every 3 months or so, then when we needed new records mine that data for anything of value, add back in and attempt to warm up. If your Marketo is integrated with Salesforce, though, there’s a more sophistacated approach that manages the ‘remove from Marketo’ automatically while mainting the data in Salesforce in case any records enliven later on. Here are the steps:

• First, make sure you have the ‘Marketo – Do Not Sync’ field available between your Salesforce and Marketo. You can ask Marketo support to enable this field for you.
• Next, if you don’t already have one add a TRUE/FALSE field to indicate if the record has been ‘Deleted from Marketo’. Sync this field with Salesforce with a default value of false.
• Create a Smart List in Marketo of all records you’d like to delete on a rolling basis. Records with no Activity in the Last 90 Days, for example.
• Now, create a Smart Campaign in Marketo that keys on this Smart List. In the Flow Step, first set the field ‘Deleted from Marketo’ to TRUE and set the field ‘Marketo – Do Not Sync’ to TRUE. In the next step, sync the record to Salesforce. Add a wait step (maybe five minutes) then set to ‘Delete from Marketo’ but not from the CRM.
• This Smart Campaign, then, keys on your Smart LIst to regularly find the records for deletion, sets the proper fields on these records, syncs them to Salesforce, marks they so they don’t come back to Marketo, and deletes them from Marketo.
• You can track the records in Salesforce that have been deleted from Marketo by using the ‘Deleted from Marketo’ field.
• If you have duplicate rules on in your Salesforce and the record happens to come back in to Marketo – the duplicate rule will catch the record as it attempts to come in to Salesforce from Marketo. You can create a Smart List in Marketo to review records that have failed to transfer to Salesforce.
• The Smart Campaign in Marketo looks like this: