Stanford’s Guidelines to Web Credibility:
Avoid errors of all types, no matter how small they seem.
Typographical errors and broken links hurt a site’s credibility more than most people imagine. It’s also important to keep your site up and running.
We all make mistakes. The worst are the little things that are often overlooked but easily correctable. Before publishing new content on your website, take a few extra minutes to run the content through a spell check program. Even if you’ve made a only few minor edits, don’t assume that you don’t need to double check your work.
Just like any other form of medium, it’s best to get a third party to proof read your site’s content. Undoubtedly, they’ll find something you missed even after several proof reads of your own.
Aside from spelling and grammar, you should check your site regularly for broken links. Allowing visitors to find broken links on your site is just another way of letting them know that your site is outdated or that you don’t have the proper infrastructure to handle their needs. This is as good of a reason as any to leave and purchase from a competitor instead.
Regularly check your site for broken links. There are plenty of online tools that will spider your site and give you a broken link report quickly. Even if you have not made changes to your site in a while, running a broken link check will identify links to external pages which may have changed or been relocated. Regular checks will ensure that all links, both internal and external, are completely functional.