What is wrong with companies? I want to buy things, so I go to their web site, only to be faced with a Byzantine site that is slower than molasses, and about as helpful as a hole in the head. So I send them a simple email, like what is the difference between X and Y, or where can I buy your goods, and what happens? Nothing, not a sausage!
Now some companies get it, the site is fast to load because they thought about their design, and kept the graphics to a minimum, carefully designed the HTML, and haven't used toy technologies like ASP, or lumberingly slow ones like JSP. Whatever you may say about Yahoo or Amazon, they do take in lots of money, and their sites on the whole mostly work.
What really is really annoying is when a small company with a fairly limited product range, gets a typical "crap" site:
This is really annoying. This spring while out walking in the Yorkshire Dales, we past by an outdoor goods shop, and I bought a very nice walking/travel shirt, that was very reasonably priced, and I rather liked it. I've seen the brand advertised before, but not on sale anywhere, so I tried their site, and was very disappointed. How can they have such a cool shirt, and such a crap site?