Quick Guide to Geofencing: Centroid vs. Polygonal Geofences

April 29, 2021

Have you ever heard of a geofence? As a marketer, it’s very likely that you have. Whether it’s for ad targeting purposes, gauging the visitation numbers for a specific area, or maybe to determine if a certain location gets the type of foot traffic that you are looking for. 

Do you know what geofencing actually is? Imagine building an invisible fence around a specific area. When someone crosses the fence, the developer or administrator can configure it to send ads, push notifications, or simply to count and measure the foot traffic inside. In this post, we’re going to take a closer look at two specific types of geofences and what they can do for your business.

Quick Guide to Geofencing: Centroid vs. Polygonal Geofences

Centroid Geofences

Centroid geofences allow the user to create a radius around a point of interest to a predetermined distance. With this, users are able to target or collect data for those who are moving within that circle. While this method is fast, oftentimes the data collected can be unreliable. 

Since centroid geofences use latitude and longitude and geographic centerline coordinates, targeting a very specific location of interest is difficult. 

For example, you own a retail shop in a shopping plaza and want to determine what percentage of the plaza shoppers are visiting your store. With a centroid geofence, you can see who is shopping at the plaza but can’t narrow it down to your store. Also, there wouldn’t be a way to determine if all of the data here is limited to just the people shopping in the plaza as it might pick up signals from the park down the street or the gym that’s a mile away.

Polygonal Geofences

Unlike centroid geofences, polygonal geofences allow the user to manually map out an area of interest instead of letting a beacon of a generalized area run the show. This type of geofence ensures that you are gathering data only from an area that interests you and is much more customizable than its centroid counterpart. 

Although you are able to customize your area of interest, it doesn’t mean that these fences can’t be large. For example, you are a marketer that wants to set a polygonal fence around your big box retail store in Burbank, CA in order to send out custom sale ads and coupons to your shoppers. Instead of just using your geofence to measure loyal shoppers, you could also use it to understand consumer activity around your store. With this in mind, you extend your fence to cover the parking lot, the cafe around the corner, and the park next door. 

On the other hand, if you want to gauge how many shoppers visited that little cafe after visiting your store, you can adjust your fence to only cover that cafe. 

Let’s say that you want to determine the foot traffic in the general area, but also want to know how many people are visiting the cafe, specifically. With polygonal geofences, you are able to create two fences. One around your store and the surrounding area, and the other one, around the cafe alone to ascertain what percentage of visitors are visiting the cafe.

Which Geofence is Better?

After taking a look at both geofencing options, it’s easy to determine that if you want accurate and precise location data for a specific location, polygonal knocks centroid geofencing off of the charts (at least for marketing purposes).

Because polygonal geofences allow the user to narrow down a location of interest like the selection tool in Photoshop, marketers have the advantage of being able to make accurate data-driven decisions instead of relying on “maybes” and “perhaps.”

Polygonal geofences let you surround only the specific area that you are interested in which improves the data quality and enables precise audience targeting.

Import Your Own Geofences into Gravy APIs

At Gravy, we use polygonal geofences to ensure data accuracy. Gravy APIs allow you to import your own geofences or even use ones already created by us. With Gravy APIs and applications, you only pay for the data that you need. This means that you spend more time analyzing data instead of sifting through large data sets. For more information on how Gravy’s geofencing strategy and how your business can benefit from location intelligence, contact us to speak with an expert today.

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