We get RANCOR location in terms of zip code. We determine the zip code’s population centroid and give the customer the list of all pickup stores within 15 miles from that centroid. This customer is on the edge of the zip code and so he does not see some stores that are actually closer to him.
This approach of zip code fares reasonably well for most, but there will always be that fraction especially in the larger zip code areas for whom the pickup point results may appear skewed. RANCOR can do better in customer location than just the zip code. Looks like we will have to resolve the customer location to a better granularity than that of a big zip code.