Website monitoring typically involves using a service to check your site at regular intervals for various problems that might impact visitor experience and your sales. The most basic checks test for availability - if someone goes to your website will it be available for them? Websites often go down, especially during peak holiday periods, and you may be too busy to even notice - you'll just keep missing sales until an angry customer calls to complain.
Speed is also important - people want a fast online shopping experience and, if your website is slow to load, you are going to frustrate shoppers and drive them away (and they are unlikely to come back). Again a monitoring service can help by providing detailed reports on multiple pages on your site.
The article also talks about some less commonly used checks that can look for things like outbound links and/or products you don't want to feature on your website.
I'm very grateful to editor Kate Penn for considering this topic and letting me contribute. The article will appear later this summer or early in the fall. Because of space constraints some material always gets cut so hopefully we can get the expanded version up here once it comes out in print.