Updated from March 2010
What is the difference between Address Validation and Google Maps?
Deliverability, deliverability, deliverability. Okay, there are a few others, but that’s the big one. Just because Google Maps places a marker on a map when you input an address, does not mean that you can deliver mail there, nor that a property even exists at that marker.
Take the following “address”:
4130 Calle Real Santa Barbara, CA 93110
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As you can see, Google Maps says this is a valid address and puts its marker next to an empty field with no buildings. As you’d expect this is not a deliverable address and will be returned to sender.
The reason for this discrepancy is that Google Maps is not an Address Validator, it is a Geolocation Estimator that uses addresses to aid in its estimation.
Imagine two people each holding a ruler with the numbers 1 – 12 printed on it. One of them is blind-folded. If they were asked to point to the number “6”, how would each one go about it?
The one who could see all the numbers would just find the 6 and point to it. The one who was blind-folded would probably guess that 6 was printed right in the middle of the ruler and point there.
But what if the ruler was missing the number “6”? Well, the person who could see all the numbers would state that the number was invalid, and the blindfolded person would point to an empty space in the middle of the ruler.
Google is blindfolded. They know street names, and the numbers on the endpoints, but very little about the numbers in-between. Often they assume a continuous and evenly-spaced number line and point to where they’d guess your number is.
Admittedly, this is an extreme example. But what it demonstrates primarily is that Google Maps does not have a strong knowledge of valid primary numbers within street segments and therefore cannot be used to determine deliverability of an address. The only thing that can reliably determine deliverability is a CASS-Certified Address Validation Engine that can match an address against the USPS database of valid addresses.