Let's breakdown the data that you're seeing on the Dashboard page.

Using the screenshot above for reference, lets examine the various components.

This is the total number of net-new profiles as identified from sessions during the selected time period.

This is the total number of previously identified profiles that have returned to your website and have been identified during subsequent sessions during the selected time period.

This is the total number of times that your site has been loaded by users whom we have been able to identify (aka sessions).

This is the total number of page views generated by identified visitors (aka sessions) during the selected time period.

A session is a visit from a user that we have been able to positively identify as being in the United States. If someone is using a VPN or a proxy, it can greatly affect our ability to confirm that they're in the US. If we can't confirm that they're in the US, we abandon the identification process because they could be European and spoofing their location (as one does with a VPN or proxy). Our session count almost always varies (lower count) from what you would see in something like Google Analytics - because they aren't governed by the same rules as us.

Once we know they're in the US, other things that can affect our performance are private browsing or a user recently clearing their cookies or using a new(er) device. If they don't give off signals about their identity on purpose, it hurts our chances - which is understandable.