What if your widget is great, but people would really love it if they could see it in action?
The album is great but with no airplay, nobody knows that it sounds great?
A picture is worth a thousand words, but you don't have the space for a thousand words?
If you own copyright to your television commercials, you could even add these into a web site.
The WWW allows you to add sound, pictures and short movie files to your company's information if that will serve your potential customers. No brochure will do that.