Traffic source analytics question (i.e. Yelp)

I only have the business account and not the full commerce buildout. I was trying to figure out if any Yelp users who visited our website (we don't have a physical location) actually bought anything.

It looks like Google Analytics is showing that all the purchases came from secure.squarespace.com/referral and not from any of the linked traffic referrals like Yelp or a website my friend advertises our coffee on. It seems unlikely that no one coming from the other links purchased anything.

Is this a consequence of not having direct Squarespace analytics and Google Analytics somehow only recognizing purchases as "referred from" the checkout page?

Just trying to do some quick calculations on where I might get some more bang for my traffic buck.