Hi Frank,
Thanks for your thoughts. The Hubspot report I’m looking at is here: Reports > Analytics Tools > Links. Just to be clear, I’m not looking at the Traffic Analytics report but rather in the Links report.
It appears that Hubspot just pulls the initial data from Moz when you create an account and then adds any new referring domains it sees come through. Moz, on the other hand, relys on other services, like Majestic, that crawl the web on an ongoing basis looking for links. These different methods produce very different results I guess.
Thanks again for your reply.
Eric