It is important to keep in mind that a good web site is a continually evolving entity. In most cases, a successful web site will be updated at least monthly, and extensively reviewed and enhanced at least twice a year to bring it up to date with the current Web technology and to keep it competitive with other ongoing Web developments. So just because a Web site is redesigned does not necessarily imply it is a failure. Nonetheless, it is probably true that more Web sites fail than succeed. Poor planning is often a problem.
Poor execution can also be a problem.
Failure to design for the Web medium is a common mistake. Many companies think that putting their corporate brochure and sales literature on their Web site will provide them with a Web presence, but this practice usually fails because a good Web site is much less passive and more interactive than a print brochure. While Web page design is syntactically simple, building a professional appearance and an effective marketing message is not as simple. Poor promotion is usually the biggest problem. Companies often do not realize that sometimes a comparable level of resources should be invested in promotion of the site as in its actual development.