I was shopping online the other day, and I wanted to buy some boots from a famous western boot manufacturer. They’ve been around forever.

My shopping experience went fine until I decided to check out the location of the closest store to my house. On one page, it asked me to enter my zip code, promising to locate the nearest store.  But the information would not pop up, despite repeated tries. All I saw was this message: “System Error: Please try again later.”

As shoppers, we’ve all experienced instances like this, and, at worst, they’re minor annoyances. But, as the owner of a site, this is no small matter because consumers have a very short patience span on the web. It’s most likely that they’ll close their browser or return to the search engine they were using, in this case, to find boots elsewhere.  And to a business owner, that means lost sales.

But a good website transaction monitoring service can check your e-commerce application every five minutes or so and notify you about any problems.  This year, Forrester Research is projecting online retail sales to rise 11 percent, to $156 billion, growing to 7 percent of overall retail revenue (from 6 percent in 2008).

So, this is an incredibly valuable service to have for the holiday shopping season, and it’d be well worth it for you to make an investment in prevention, considering what you could lose.