A planned, but non-existent, product, like vaporware but with the added implication that marketing is actively selling and promoting it (they've printed brochures). Brochureware is often deployed to con customers into not committing to a competing existing product.
The term is now especially applicable to new websites, website revisions, and ancillary services such as customer support and product return.
Owing to the explosion of database-driven, cookie-using dot-coms (of the sort that can now deduce that you are, in fact, a dog), the term is now also used to describe sites made up of static HTML pages that contain not much more than contact info and mission statements. The term suggests that the company is small, irrelevant to the web, local in scope, clueless, broke, just starting out, or some combination thereof.
Many new companies without product, funding, or even staff, post brochureware with investor info and press releases to help publicise their ventures. As of December 1999, examples include pop.com and cdradio.com.
Small-timers that really have no business on the web such as lawncare companies and divorce laywers inexplicably have brochureware made that stays unchanged for years.