Leads created by BrightTALK in Pardot will default to having a blank "Source". We recommend updating this so that you can easily distinguish between leads created by BrightTALK and leads created by other API integrations. To do this, you can utilize a single, universal Automation Rule:
Once this Automation Rule is active, all leads created within the last day that have a BrightTALK User ID will have a default Source of "BrightTALK." Feel free to change the final parameter to whatever you need it to be (i.e. instead of "BrightTALK", you could do "BrightTALK Webinar").