Even as online retail struggles, you can keep sales figures alive by optimising the site you have. One area to look at is improving what happens to your customers when things go wrong.

A classic and expensive error

During my previous life as a developer, I lead the prototyping for enhancements to a clothing and home wares website. Like any sensible UCD practitioner, I wanted to get measurements to help me understand where customers were going on the current and revised site.

Just one error message

When it came to errors, the need for more detailed measurements was particularly urgent. We didn't know which pages or processes were throwing up errors. We had no detailed analytics and only one error page for the whole site: "An error has occurred. Press Continue."

I knew that we needed to write individual, polite messages which would reassure people enough to carry on, but we didn't even know yet what those errors were.

Once the analytics were up and running, we could quickly see which pages occured before and after the error page. This let us identify the user journeys where the errors were triggered. So we were able to write custom messages, things like "We're sorry, we've had a problem processing your order. Your card hasn't been charged yet. Please click checkout to try again." We also provided a customer care number together with a code for continuing the transaction offline.

Return on investment

Within a month the percentage of completed purchase journeys increased a modest 0.5%. Putting it in some perspective that 0.5% was worth £27,000 a month on average - or over £250,000 per year.

And all this was hypothesised, diagnosed and implemented over 2 weeks, at a staff cost of approximately £8,000. That's a great return on investment from paying attention to the detail of the customer experience. Each one of those customers had a chance to complete their purchase, and to remain a loyal customer with a chance of purchasing again in future.

6 error message tips

If I've inspired you to revist your site's error messages, remember these golden rules as you go:

• Be polite: Don't make your visitor feel like they've done something wrong; accept responsibility for the problem, say "sorry", "please" and "thank you".
• Use plain English: Remember that the people visiting your site aren't developers, and don't know Java from JavaScript or 404 from 500 (unless you're writing error messages for Slashdot or the MSDN that is).
• Reassure: Especially when the visitor's money is at stake, it's important to make sure that people understand that nothing catastophic has happened.
• Make it brief: Your visitor isn't interested in the exact whys and wherefores, be succinct.
• Help people recover: Provide them with a clear path out of the woods - even if that means calling someone on the phone.
• Tag them: Track where people go and what they do before and after experiencing an error on your site, and track what happens as you make changes.

Optimising is just one of three design-based strategies for beating an economic downturn:

• Innovate
• Optimise
• Cut costs by improving the customer experience