Scientific researchers – useful chaps that they are – have just confirmed what married men have always suspected: nagging is a highly effective means of persuasion.

Researchers have also confirmed that people who are physically tired are also less likely to resist requests.

These rather obvious observations are, however, of limited value to the entrepreneur. It may be possible to wear a potential customer down, but it is highly unlikely that such a customer will ever come back.

Instead here is a short list of measures the entrepreneurs can take that might, just might, give a slight edge in any negotiation or selling situation, without putting the customer off.

What follows is, as ever, the counsel of perfection – easier said than done:

1   Persuade Personally – a meeting in person is more effective than a hundred telephone calls or a thousand letters, because it is psychologically far more difficult to say “No” to someone right in front of you

2   Choose the Time and Place carefully – fight on your own ground whenever possible

3   Plan your Pitch

4   KISS  – Keep It Short and Simple

5   Rely on Quality Not Quantity of Arguments – someone who is reluctant will seize on your weakest point as a pretext to decline your suggestion

6   Eye Contact – you should be in eye contact most of the time, but do not stare so constantly that it becomes creepy

7   Demand a Response – do not leave things hanging in the air but end in a way that compels a decision.