In April 2015, I wrote about Google’s progress in steadily tracking more and more user locations to ZIP codes. As ZIP codes are the most granular location type which populates the “Most specific location” field in AdWords geographic reports, the share of traffic that Google assigns to ZIP codes in this field gives advertisers an idea of how well Google is doing at figuring out searcher locations.
At the time, Google was showing strong progress in its location tracking:
Fast forward to today, and Google is tracking more searchers to ZIP codes than ever before. However, most of the progress made only applies to google.com traffic, while search partners are continuing to lag in terms of the share of searchers tracked to a ZIP code.
The most important thing to keep in mind with this analysis is that it is based on the locations that Google itself reports. This means that if Google were to, say, expand the use of modeling to infer searcher location to apply to users whose locations it is less confident in, we might see a rise in the share of traffic tracked to a ZIP code without any change in what information Google is actually getting.
As such, the trends shown here could be the result of updates Google itself made in assigning and reporting searcher location, rather than Google actually obtaining more granular information on searcher location over time. They could also be the result of a combination of Google changes and more granular information.
Across the board, Merkle advertisers are finding more and more traffic attributed to ZIP codes in the “Most specific location” field in AdWords geographic reports. Looking at google.com traffic specifically for one advertiser, we find that while 28 percent of all traffic in Q1 2015 could not be tracked to the ZIP code level in this field, that figure was just 11 percent in Q4 2016.
The share of traffic tracked to ZIP code has risen for all device types over the last couple of years:
Google continues to track more searchers to the ZIP code level on desktop and tablet computers than on phones, but the gap is now much smaller than it was two years ago.
Search partner location tracking is also getting better, but no device type topped 80 percent in share tracked to the ZIP code level in Q4 2016. As with google.com searchers, phone searchers are less likely to be tracked to a ZIP code.
As such, it’s apparent that Google isn’t always receiving the same information from search partner sites as it gathers when searchers are on Google’s website. It could be that there are specific sites which have issues, or it could be that this is just a complication Google has with all of its search partners.
Either way, Google’s progress in tracking search partner user locations at the ZIP code level is rather muted when compared to the significant leaps it has made in tracking searcher locations on its own site.
