If your business has a website, most likely it's constantly changing and evolving. This can be a good thing but how you handle these changes can make a dramatic difference in how effective your website becomes.
Some of your content may be time sensitive, such as information on special promotions, contests and things of that nature. Some content may no longer be relevant to your business, such as discontinued products or services. Most people's first course of action in these cases would be to simply remove these pages and all internal links (links from your own website pointing to your own pages) so that there is no path to them. This is not the best approach and can result in less website traffic and also potentially affect your search engine rankings.
There is a strong possibility that other people have placed links on their website pointing to the removed pages. Some people may have even previously book marked the removed pages for future use. Once you've removed the pages you have eliminated these sources of prospects.
Search engines follow links to find websites and web pages. By removing these pages, you are removing the content that they have come to expect (once they've found and indexed it). If they are unable to find a number of pages that you have improperly removed from your server then they very often will leave your website. This can make getting your new pages indexed difficult and slow.
Fortunately, the solution is relatively simple. If you plan to remove a page from your website you would first set up a 301 redirect to another related page. For example if you had a page named "july-sale.htm" and it is now August, you would set your 301 redirect to automatically send all requests for that page directly to "august-sales.htm" instead. Once that is in place you can safely delete the page. If you've already deleted pages from your website without setting up 301 redirects you can still fix the problem. If you view your error logs on your web server you can find all of the 404 errors which are caused by requests for files that do not exist and then set up a 301 redirect for each missing file.
This ensures that when someone comes to a page that no longer exists, rather than getting an error message and leaving, they are instantly whisked away to the next most relevant page and you get the chance to turn them into a client or customer. It also ensures that when the search engines come looking for a page that no longer exists they are redirected to the next most relevant page causing them to spend more time crawling your website. It's important to point out that some hosts do not offer the ability to set up these type of redirects and will recommend adding a java script to the page. This will not work for the search engines because they do not execute any scripts, and it will only work for a portion of visitors.