I'm not sure if the paywall referrals property is working correctly

We're opening up our paywall to people referred from Facebook and Twitter. That way they won't hit the paywall and stories won't count toward the paywall. But in testing it it looks like the views are being counted until 0 articles remaining and then it just continues to let future articles be viewed. I thought they would just not count period.

For instance if we have 10 free articles and someone views two from our website and then two more from social media they would then have eight remaining. But it seems to say they have six. Then it continues to deduct views until it reaches 0 at which point it just continues to give them the free views.

And one thing the documentation doesn't really make clear is whether this custom property has to be an EACH page behind the paywall or if it just need to be on our root URL. For instance can I just have it set on / or do I have to set it on /local_news/, /local_sports/, /life/, etc?