I have a question about an idea I implemented on a website. The main question is why doesn't anyone else do it? The face that NOBODY does this (not even the big ecommerce sites) makes me believe that there is a reason for not doing it.

So here is the deal....My Son is attending college up Anchorage Alaska and during his time up there I wanted him to learn what it was like to run a business. So we came up with a simple website business idea what works in his area so that he could learn first hand what it is like to run and operate a business. I created him a site via the Coffee Cup HTML Editor:

Santas-Nice-List.com

He basically sends out letters from Santa to kids around Christmas time. It works out great from his location because you can actually get the Anchorage post office to post mark letters from the North Pole.

What I did with the site, that I wish more people would do, is to always request the ZIP first whenever I need the user to input an address. I then use AJAX to lookup the ZIP in the background and fill out the city and state for the user. I usually put the phone number or something else after the ZIP to delay the user so that AJAX can fill out the City and State fields before they try to; although it only takes a plit second to make the query and fill out the data automatically. It works perfectly and really cuts down on the user input making everything flow faster. Why don't we see this implemented all over the place? Isn't this what computers are supposed to do?

As stated above, the fact that we don't makes me wonder if there is something that I am missing that would not make you want to do something like this.

Thoughts?