How to get demographic data: There is a theory that "birds of a feather flock together", therefore people sharing ZIP or Postcodes share similar demographics.

These postcodes have characteristics in common with other postcodes with similar demographics.

There are companies which analyse your database and break out the postcode types of your best or most frequently occurring customers.

You then mail or doordrop to postcodes of the same type.

It is hard to form an opinion on this, there are many areas of mixed housing, also how much do you have in common with your neighbours?

A UK magazine visited some postcodes suggested by the major companies and found varying degrees of accuracy.

Another method is Lifestyle lists where people answer long questionnaires about purchasing habits as well as personal data. You can have your list profiled against this list, matches made will make it possible to find similar prospects from the list.