Launched in September 2016, the Google Possum Update changed the order of local results to depend on the searchers’ location relative to the nearest business. This was more evident on mobile devices.
One of the main things that Possum updated was the filter that applies to local results and it was thought to be one of the biggest updates since Pigeon.
It is thought that the main intention of the update was to diversify the local results and prevent any spam pages from ranking.
In the age of mobile devices and micro-moments, users are often searching with intent and the physical location of the searcher is now more important than ever to Google. These changes were implicated as a way of improving the experience for users searching for local services by ensuring that the results are diverse yet relevant.
The update seemed to mostly impact the ranking in the 3-pack, which is the group of 3 businesses shown on a map on the SERP, as well as the Google Map results.
The Possum algorithm had a positive impact on businesses that were located on the outskirts of a cities boundary as they saw a huge increase in their local ranking. Beforehand, these businesses would struggle to rank for keywords regarding location because they could be viewed by Google as not being located within the physical borders of a city.
Other changes included Google now filtering results based on address and affiliation. The purpose of this was to avoid duplicate content from a company, however, this has resulted in a lot of businesses being filtered out and struggling to rank where they once did. From an SEO perspective though, a strong NAP audit (Name, Address, Phone number) and a good local SEO campaign should be able to restore any slipped rankings.
It also seems that the local filter now runs more independently from the organic filter. If Google was to filter your website from the SERPs organically it would result in a negative impact on ranking position. However, since the update, there are many businesses that now rank well for competitive terms that link to pages that are filtered organically.
Another thing to consider is that since the update, it is now increasingly important that you check where your location is set to when tracking ranking positions as the algorithm now means results will vary place to place. Results will also differ depending on any slight variations of the keyword.