The main goal of any online business is to be easily found online. This is done by practicing good SEO techniques to become search engine friendly. A website that is not optimized for search engines will not be found in an online search. The goal is to obtain a result that will appear on the first page for a search result.
At one time, having a business card was the mark of a professional, trustworthy company. Nowadays, it is unheard of for such a company not to have a website. However, even the world's best-designed website does no good if it cannot be accessed by prospective customers and business partners. This is why server "up time" is so important.