When installing Beacons in your venues, it is a necessity that the UUIDs be used alternatively. This means for instance that the UUID 1 (73676723-7400-0000-FFFF-0000FFFF0001) must not be used for a Beacon next to another with the UUID 1.(See also about this topic "How is Beacon ID structured?")
This is important, since iOS can monitor only up to 20 regions. Regions can be either Beacons or geolocations. By changing region, the app will be "awakened" - important for apps in the background.If this condition is not met, it may happen that no action be delivered to the user as he goes from one Beacon area to another's.
In particular, this is important when many Beacons, e.g. of Estimote, Radius Networks, etc. are used simultaneously
The alternative placement of UUID ensures that all actions will effectively be delivered to users.