Rowan W said:
You don't get it; designing for 800x600 means your site will be fully viewable on 98% (800x600 up to anything higher) of monitors instead of just 78% (1024x768+).
The extra 2% (if that) would be on PDAs, etc...
Unfortunately, my friend, it is you who does not get it.
First and foremost, and clearly stated by the rest of my post, I design for 640x480, let alone 800x600.
Secondly, many times, especially with interactive storefronts that require API or other checkout software, 800x600 is simply too small a resolution to display all the necessary content in a fashionable matter. (Listings often contain long titles, and multiple item orders and destroy the flow and construction of a site).
With that said, marketing research shows that designing a site towards the smaller 20% of users generally results in turning off a larger percentage of customers who are using better resolutions -- With less viewable content and more required click throughs to get through the surfing process of a site for higher resolution users, you are essentially doing nothing more than accomodating a small number of customers by alienating a potentially larger number.
In almost all cases, with automotive sales being the only true scientifcally concluded exception, you will generate more business, and maintain more return business by triggering the larger chunk of the market, not everyone possible.
The reason I use 640 is I find it to be tremendously clean, and considering I am establishing creative media and marketing for people who may not even have computers alltogether, its best to allow them to have comforting access no matter their resources. My situation, though, is very unique, and that is why I can plainly say that you really don't understand.
Marketing and Media is chess, not checkers. It's not splurge art.