Here's a product webpage that doesn't include screen shots. It doesn't event tell you where to find them.
When you dig deeper there are some thumbnail screen shots, but even they don't lead to full size images. The thumbnails are all you get.
This is a basic mistake, and I think it lets the product down badly. The product, TopDesk, is a leader in its field. (link courtesy of the Daily Grind)
Every software advertisement should include screenshots.
** Even 'Windows Services' that don't have a GUI **. Tattoo that on the back of your eyeballs (as William Goldman would say).
There's always a way to include a screen shot, and it's the first thing that people are looking for. Once they've seen your product, then they'll have a place in their mind to store the facts and figures, the features and the detail. They'll have questions, too, and hopefully the writing will answer their questions.
Check out the front page for blogjet. That's better. A screenshot. And best yet -- the screen shot takes you to more screenshots. I feel like I know that product now. And if you know a product, well, you start to care about it. It's not just vapour.
CodeSmith's front page is another good example. It's real. So is DotPost.
This need for screenshots is probably a corollary of 'The Iceberg Secret' that Joel Spolsky writes about, and that you can read about in his book, which is like the website but a hell of a lot easier to read in a stranger's bed.
Okay, enough preaching for one post.