It’s my favourite film.  I have lost count of the number of times I have watched Casablanca and I still enjoy it just as much.  When Ilsa (Ingrid Bergman) walks in to Rick’s (Humphrey Bogart) nightclub for the first time it isn’t hard to see why both leading men adore her.

I am not the only person to know how much first impressions really do count.  In a study undertaken at Oregon State University, a series of videotaped job interviews were viewed to test whether it was possible to guess the outcome simply from observing the interaction between the interviewer and interviewee. It was found that an observer could accurately predict whether or not the interviewee would be offered the job by simply watching the first 15 seconds of the tape - the handshake, the "hello" and very little else.  What happened in those few, brief moments was enough to determine the candidate's future.

Whether we admit to it or not, we all use subjectivity to make selections.  We choose doctors, dentists, motor mechanics, and plumbers to provide services to us and yet few of us are really qualified to assess the capability of these professionals to deliver each of the services.  In most instances we probably decide on the basis of which potential provider looks and sounds most credible.

I started my first job in what was then an internationally renowned clothing store in the West End.  After three days they told me to go and pick a suit for myself.  I could have it for free.  I was astonished.  After trying on a few I chose one.  It should have cost £175.  Doesn’t sound like much now but this was a long time ago.  I looked it up; that’s the equivalent of £2,575 today.

So why on earth would they give an 18-year-old trainee a suit like that to wear to work?  “Simple,” explained my Manager. “First, we are going to make you look as if you know what you are talking about.  Then we are going to teach you to sound as if you know what you are talking about.  Finally, if you listen and learn you will know what you are talking about.  And because you look and sound credible, people will listen and take note of what you say.”

This isn’t an article about what you should wear at work.  It’s a reminder that, from the moment you first engage with customers they are assessing you and your company and deciding whether they are going to do business with you.  A lack lustre response, an ill-considered comment or a failure to sound upbeat and positive with a ‘can-do’ attitude and they will take their business to one of your competitors.

Sit down with a friend.  Discuss what you want him or her to ask.  Put the phone on loudspeaker and get them to ring your company.  Listen to the way your people respond to your customers and make sure you are happy with you.  If not, arrange some retraining.  After a while repeat the exercise and make sure there has been an improvement.

Take the same approach when writing for customers.  Your website or your sales brochure might be the first thing a potential new customer sees so make sure it gives a positive impression of your company.  And if you are not sure if it does, ask someone who will genuinely tell what they think to take a look – and act on the feedback.

Remember, you only get one chance to make a first impression.