The auto-calibration feature was designed to ensure that impressions are being tracked accurately from AdStash units. To do this you must download the AdStash installation mobile app on Android or iOS from the app store. The point of this process is for AdStash to determine the distance from the screen that impressions can be counted from and be deemed viewable.
This policy is based on 3 factors:
- The size the screen
- The size of the room the screen is installed
- The environment the screen is installed
1. The size of the screen
Here are the assumptions & rules this is based on:
Therefore, a diagonal screen size of 30” results in a 50ft tracking area. This progression (based on the Snellen eye chart3) is linear, meaning if the screen size doubles so does it’s tracking area (60” screen results in a 100ft tracking area). The installer of the device must take 3-5 photos of the screen using a mobile app with location services turned on, to validate that the screen is indeed that size.
- 20/40 vision uses 87 point font size, giving the font 18mm in height.
- Therefore all traffic must be able to read font 10% the height of the screen, from 20 feet away.
- The Snellen chart is described here
2. The size of the room
All rooms are put into 1 of these 5 rooms types:
3. The Environment
The installer of the device must take 3-5 pictures of the environment with location services turned on through the app to validate that the screens viewability is not obstructed. For example, a screen in a grocery store may be 50” but in the middle of a grocery aisle, therefore its tracking area is significantly limited because of restricted viewability.