Jim Delli Santi, a former Yahoo executive and now the CEO of Spotlikes, last week said some very interesting things in a comment to another post. At Yahoo they determined roughly four years ago that 30% of US search queries carried a local intent. In the UK it was about 40%, according to Delli Santi:

At Yahoo we identified accurately that 30% of our search traffic had local intent, (4 years ago) growing to 40% quickly.  In the UK local search intent was typically 10% higher that US queries.  On mobile this is of course much higher.

Google has loosely said that about 20% of PC search carries a local intent. However, I questioned Google about this a couple of years ago and they told me that it was a reasonable estimate beyond which things became ambiguous.

I asked Delli Santi how they determined local intent when he was at Yahoo. Here’s what he said:

The WhereOnEarth geo-taxonomy engine we purchased in the UK let us analyze extremely high volumes of local search queries that had any type of location associated with them . . . We ran 100M user search queries through this local query engine which provided a tremendous amount of insight about local intent.  We were able to “isolate” those search terms that signaled local intent, because they were most often searched along with a location, e.g. “pasadena dentist”, “mechanic in san jose, ca”, “attorney 90210″. This created a large corpus of search terms that signaled local intent like mechanic, attorney, sushi, burrito, etc.

Some notable insights on which we authored (and were granted) our patents:  8% of all queries had a location explicitly included in the web search term… but 30% of 100M search terms had “local” intent, e.g. dentist, contractor, lax, parks, pediatrician, etc..

We could also tell “local intent range” of the search query;  e.g. the query “used cars” was most often searched using locations that had distances up to 50 miles, (used cars los angeles), while other local search terms had local intent ranges far smaller or at the neighborhood level such as “dry cleaners 92010″.  So if a user searched for dry cleaners, or used cars, it would follow that you’d want to serve local ads that were up to 5 miles away for dry cleaners and up to 50 miles away for used cars.

This is fascinating stuff. I’m sure what Delli Santi is saying is correct. I also don’t imagine there are significant differences, in terms of local intent, between Yahoo and Google users. In other words, I don’t think Yahoo users are more “locally inclined” than Google users.

But in the interest of being cautious I think we should “split the baby” between the Yahoo and Google numbers and use 25% as the new benchmark for local search volume on the PC. According to comScore there were 18.3 billion search queries in the US in March:

If we use the 25% figure that would mean about 4.5 billion local queries across the major engines in March in the US — at least.