We recently had the following unfortunate experience. After focusing heavily on marketing, we launched a new marketing campaign. Soon we had an irate email. A gentleman pointed out he could not get the free download nor could he place an order. We had already received orders, so we were just about to dismiss this as the writings of a computer illiterate, who probably had trouble turning the thing on, when we decided to check it out.

And to my horror he was right! We have two identical sites, with different domain names, and I had just spent a small fortune promoting one of them, to find it was not possible to place an order! It took only a few minutes to find the problem - wrong links to the order page. I had checked this before, but somehow the page was subsequently changed and uploaded. He later informed me that the free download was not downloading, despite a free bonus (a "thankyou" for bringing it to my attention) downloading perfectly well.

We tried - and again, he was right! We couldn't see the problem, so we just uploaded a "fresh" version, and it worked. I don't even want to think how many customers we might of lost - most people will just abandon your site, rather than take the time to let you know something is wrong. So this chap could have saved us a fortune - so I sent him a free bonus! He was as pleased as punch, and I was grateful that someone out there took the time to point the problems out. He is my best customer - he hasn't purchased anything, but he saved me from losing dozens of potential customers, who would simply "surf" elsewhere when things didn't work.

So, always:

• 1) Test everything works regularly.
• 2) Test everything works after making any changes, however small.
• 3) Test all downloads thoroughly. Things can happen that you may not ever know about problems with your ISP's server, data corruptions etc.

4) Run dummy orders to check your shopping cart and credit card processing systems work (these rely on third party companies, so you may not know if they develop problems their end).

5) Check the load time of your site, over a normal phone line. You may have a high speed connection, but most people are still connected via regular phone lines. They will go elsewhere if it takes 30 seconds to load your homepage.

6) Check all the above, on as many different combinations of computer and browser as you can. Does it look and function as it should.

7) Encourage your customers to report faults - and reward them!

There's so much choice out there, so don't give visitors an excuse to go elsewhere - make sure everything about your site works - test it to destruction!