In Local Advertising, ARP Stands For Average Rank Position
Average Rank Position (ARP) refers to the average page position of a specific domain in the Map Pack of SERPs. It is calculated by adding the position of local rankings of a domain that show up for a particular search and within the top 20 placements of a particular geography, then dividing that figure by the number of times that domain appears.
This is a metric that is used by Map Listings insight tool, Local Falcon.