A set it and forget it mentality when it comes to your site is not the right position to take.  I say it all the time...Your website is a living, breathing tool in your business.  It will grow and evolve and expand you to new levels as long as it's nurtured, cared for and looked after.  And while you may not change things, there are forces on the interweb that can change things even when you don't.  Everything is perfect and working as it should...then one day you go to your site, and the link that once worked is broken.  Or something that once looked perfect looks strange.  It's almost like some ghost deliberately got into your site and broke something...because it certainly wasn't you.

Here's the real...Your site is sitting on somebody's server.  That server is managed and updated all the time to keep up with technology and keep your website safe and secure.  Those updates can change, alter and flat out break things on your site.  So if you're not getting out there to check on  things from time to time, you need to make sure somebody is checking.  

Broken links are super common, but easily checked with a broken link checker.  A broken link sends a message to those who stumble upon it.  Even Google frowns upon them.  Sometimes that message says, "Stop...this site is trash. Leave."  Sometimes it doesn't and people want to continue on.  But because the link is broken, they may not be able to get where they want to go.  And when that's your shopping cart, that means a hot lead done gone cold!