This is a major pet peeve of mine. Not the rule, but the client who refuses to get it.
Content is what makes your site work. It’s what people (and search engines) read and look at on your site. Even these WordPress themes don’t look right unless there is something there. The best analogy I’ve been able to think of is that of a prepubescent teen trying on her older sister’s clothes. Sure you bought some fancy designer theme, but if the clothes don’t fit, they don’t look good.
Google also needs content, it can’t read images or Flash very well, and Google uses your words to determine what your site is about.
How does Google know what kind of windows you want?
Weird huh. Words have meanings. Computers are dumb and Google is only a marginal improvement. Good writing provides appropriate context as explanation
Great content isn’t easy. It takes time and practice to develop a writing style and engage with your audience and get new customers and clients. But you need to do it.
Sure, you can do a single page web site. That’s a great idea for a single-product vendor. Probably not so great if you are trying to promote multiple services, locations, or anything greater than one.