jkotuby:
I want to thank you all for the extensive and insightful answers. I think I am beginning to get the picture. Zen Cart is a Content Management System much like WordPress except that it is more complex in that it makes use of Session State as well as other functionality that I am probably not aware of at this time.
It also sounds, from the discussion so far, as if there are NO types of shopping carts that can be used in conjuction with static "flat" HTML pages, even if the flat pages have some dynamic content driven by PHP and JavaScript. Well, at least not any Carts with the complete shopping experience.
We are essentially selling ony 1 product, or variations of it...a mailing piece to be sent to the politicians of your choice. We had been working with a company that handled the Shopping page, where the site visitor would click checkboxes to "pre-packaged" mailings. However, that page was hosted on the supplier's site, and as a result we had to wait "forever" for any minor changes to be made to that page.
I am sure that we suffer now from the "back-button" problem in that scenario also. I was hoping that we could gain an advantage by placing our own single shopping page in the Zen Cart CMS, thereby allowing us to make our own changes at will.
Once again, than you all for your time and answers.
There are some simple "garden shed" systems that will turn your html pages into "eCommerce" such as simplecart.js... but I doubt whether your client wants a site that looks like his company operates out of the garden shed...
The points about selling ANYTHING on the internet these days go far beyond the issue of "how to embed html" and "can I get $1 hosting" etc...
As internet business mushrooms globally, so do the crooks who try to exploit its every vulnerability.
Most of these "tacky bolt-on shopping cart solutions" may be quick and easy to implement, and the crooks would LOVE to see more people use them because they are far easier to exploit that a robust, sophisticated CMS where a considerable part of the intellectual input has been / is being devoted to closing as many doors to the crooks as possible.
Good CMS is scalable at minimal cost. Because you are not working with "pages", but data and resources, scaling up your website in a CMS environment is vastly easier and more cost-efficient.
Flat HTML is ok for sites where the most important item on show is the family pet and a grainy picture of little Johnny's first day at school, but serious business people want proper systems - and safe systems...