Your own links may break as you inadvertantly move graphics around, or make minor changes. Or your co-workers could do something that you are not aware of. An old site is a real turn off - if a site looks like it has not been touched since the last millenium, then users are gone. And if I see broken links or spelling mistakes - I leave. Broken links Links are simply where you point to another page or website from your site.
Links break all the time.
External links to sites that you have no control over are always a problem. But even your own internal links can break for a whole range of reasons. One of the 'funniest' I have seen is when your host restores your whole site from a backup, and doesn't bother to tell you. I am sure that this has happened to me a couple of times. They obviously have had a crash during the night, and simply reload your site from an old tape.