Which makes sense to me, or at least those do not ever enforce this patent on infringers…
I have had to do zip code to location lookups to find ( I think it's called the Great Circle Calculation ) "within x miles of $zip_code".
I found plenty of companies wiling to sell me the data, sell me updated data quarterly, or API that after testing did not have data change in over a month, though from what I know about zip codes, and for our application, missing a zip code was not the end of the world, I just picked another close one. When drawing a radius around a point, if the point is missing but with so many zip codes, there was aways one close by.
1) How can they sell this? They don't apparently own it.
2) Why not use ones of the many zip, lat, long, databases that I seem to remember being pretty easy to find?
There's some logic behind the zip codes and how they are dished out. Unlike IP that has BGP to find the best route from IP to IP, USPS has none of this, so i imagine this was like trying to solve that "Traveling salesman" quandary with constantly changing and unknown locations. They had to make a sort of zip code prefix that at least gets them to the county level.
This is like how telco's issues numbers, it was all well thought out ahead of time. You could get kinda dirty and run a loop from zip_code_1 to zip_code_1+1 with each one polling the USPS for a zip code lookup. You would have a pretty accurate database. At one "scrape" of data taking 5 seconds, in a month you would have your data. After that you would only have to test the gaps between numbers to see if new ones were added or just follow some usps page to keep up on new and deprecated zip codes.
There are too many sites that use geolocation with zip to not have this be a solved problem on the very cheap. Probably just another API, where in the future apps will just be lego like API's you copy and paste JS snippets to and from. :)
I have had to do zip code to location lookups to find ( I think it's called the Great Circle Calculation ) "within x miles of $zip_code".
I found plenty of companies wiling to sell me the data, sell me updated data quarterly, or API that after testing did not have data change in over a month, though from what I know about zip codes, and for our application, missing a zip code was not the end of the world, I just picked another close one. When drawing a radius around a point, if the point is missing but with so many zip codes, there was aways one close by.
1) How can they sell this? They don't apparently own it. 2) Why not use ones of the many zip, lat, long, databases that I seem to remember being pretty easy to find?
There's some logic behind the zip codes and how they are dished out. Unlike IP that has BGP to find the best route from IP to IP, USPS has none of this, so i imagine this was like trying to solve that "Traveling salesman" quandary with constantly changing and unknown locations. They had to make a sort of zip code prefix that at least gets them to the county level.
Lot's of good data here http://en.wikipedia.org/wiki/ZIP_code
This is like how telco's issues numbers, it was all well thought out ahead of time. You could get kinda dirty and run a loop from zip_code_1 to zip_code_1+1 with each one polling the USPS for a zip code lookup. You would have a pretty accurate database. At one "scrape" of data taking 5 seconds, in a month you would have your data. After that you would only have to test the gaps between numbers to see if new ones were added or just follow some usps page to keep up on new and deprecated zip codes.
There are too many sites that use geolocation with zip to not have this be a solved problem on the very cheap. Probably just another API, where in the future apps will just be lego like API's you copy and paste JS snippets to and from. :)