How does HubSpot calculate the source of a visitor to your site?

HubSpot determines a visitor’s source from the entry context of the visit, not from the page they leave from. In the traffic analytics tool, HubSpot checks the full page URL stored in the First page seen property and the referring domain to categorize traffic into a source. HubSpot also defines Original Traffic Source as the contact property that shows where a contact first interacted with the business. That is why source attribution is based on the initial landing URL rather than an exit URL or an external analytics platform. HubSpot Knowledge Base+1