Nothing annoys an Internet user more than seeing a 404 Page Not Found error after clicking on a particular link from the search engine result pages. Internet searchers are generally enthusiastic when they find that their keyword search has yielded results. But if they are saddled with a 404 Page Not Found error, all this enthusiasm goes down the drain. They will just shut down the tab or window and forget about that site forever. There itself, the prospect of the website of getting a visitor and probably, a potential customer, are nipped in the bud.
That is the reason why you, as a webmaster, must try to avoid 404 Page Not Found errors as much as possible on your website. Even if a single page on your website shows this error, it can be upsetting, especially if that page was ranking highly on the search engines. You need to keep checking your website often, especially all the links to see if they are directing visitors to the intended destination.
But it is not possible to keep checking all the time. That is why you must think about customizing your Page Not Found displays. Instead of the routine “Page not found” message, you can change it to read something like “Sorry, our page is not functioning at the moment, but you can check out the rest of our site by clicking here.” There you can provide a link of your homepage or any other page you wish to take your visitors to. Of course, you have to ensure that that page is functioning properly, because two consequent 404 Page Not Found errors are nothing short of suicidal.
You can actually mask your 404 error page in such a manner that visitors would not recognize the page as an error page at all – this is the most common way to make the most of your 404 Error and is done via your .htaccess file. By doing so, you are actually preventing visitors from slipping away from your website by telling them that the rest of your site is up and running.