The Internet is constantly expanding, and you don't want to get left behind! It used to be that in order to have a place in this ever-growing world, it would cost the proverbial "arm and a leg" and take a lot of effort. Luckily, that is no longer the case.
Some people may say that the content of a website is more important than the overall design and layout of the site, and to some degree, that may be true. However a good layout can add to the credibility of an online presence, just like a poor design can significantly reduce credibility. How often have you been to a site that looks like it was last touched in 1995 and wonder "Is this company even still in business?" The bottom line is that the first thing people will notice when they visit your website is the design, far before they get to reading any content. The design is going to control where their eyes go first and how they will navigate the website.
All that being said about design, a website with useless content is just that - useless. If a user can't find the information they are looking for on your website, there is a significantly lower chance that they will return, which obviously is not a goal. Therefore it is very important that not only is a website full of useful, relevant information, but it must also be kept up to date. In addition, users will turn to your website when they want more information on a particular product, for example, meaning that an effective website needs to offer as much information as possible. The web is full of possibilities - use it. Audio and video product demonstrations for example are not things that can be distributed in print form like a brochure or flyer, but they can easily be distributed via the Internet.