Using Distance Bands to Rank Search Results for Business Categories
Today we’re revealing a sneak peak at another twist to our search relevance algorithm — one that strikes a balance between our traditional sponsored listings approach and pure distance-based sorting, both of which you can use on YELLOWPAGES.COM today.
The new approach is simple — we take the listings that would normally be returned by a search for a business category on YELLOWPAGES.COM, and group them into five distance bands, or rings, based on their proximity to the geographic center of the search. (We already do something similar for searches for business names; we’re experimenting with this new approach only for business/product categories.)
So if you search for “lighting fixtures” in Fremont, CA, you first see the businesses that are located within 1 mile of the center of Fremont, then the businesses within 3 miles, then 5 miles, then 10, and finally within 20 miles.
By treating all businesses within a given band as equally close to the target location, we eliminate the effect of distance within the band. So a listing that’s 4.9 miles away might appear higher in the results than one that’s 3.1 miles away, but neither of them would appear before one that’s 2.5 miles away. We can think of this as a technique for reducing the impact of small differences in distance, where the definition of “small” changes with each band. (As the distance from the center-point of the search increases, the sensitivity to differences in distance decreases. Intuitively, it’s easy to understand that the difference between 0.4 miles and 1.4 miles is much greater than the difference between 10.4 and 11.4 miles).
This approach isn’t perfect. For some business categories — particularly service-oriented ones — geographic proximity isn’t much of an issue, so it’s inappropriate to put *any* significant weight on distance when ordering the results. In others, we believe this “compromise” sorting method may do a good job of serving the needs of both users and advertisers. As always, please use the comments section below to let is know whether you think it works, and why or why not!