I am going to have to agree with George in part on this. After evaluating many dealers 3rd party data in comparison to SEM spends, 3rd party marketplaces in many cases provider a stronger ROI. If you are looking at "leads" calls, emails from Autotrader alone you are missing a large value prop. Most of the 3PP also drive highly engaged traffic to your website, this spill over can result in many cases double the leads you are seeing in the crm from the 3PP and are instead listed as "website" leads in the CRM. I would strongly suggest look at the data that exists below the crm and 3pp reports to get a clearer view.