Our metrics currently count "scans" of your beacons. A scan is when a user with a Physical Web enabled browser comes close to your beacon and either their device takes a scan on their behalf like Nearby for Android or with our PHY.net browser when it's open in the background or when a user chooses to scan for area beacons like in the Chrome widget on iOS or by refreshing the list of area beacons on other browsers.
A scan may be used to correlate a user who discovers your beacon. So if you have a beacon in a high traffic area with many Physical Web users, you should see more scans of that beacon then a beacon that is in a low traffic area.
When using metrics, you are able to pick and choose what you would like to see like total daily scans or average scans as well as the time frame which you would like to measure.
*Please note that the way in which Google chooses to scan for area beacons in Nearby and Chrome may produce under-reported scan metrics because of caching.
We're currently working to improve our metrics so watch for updates in the near future.