Adcept is the halfway house in the CREATIVE process of producing an advertisement. As the name suggests, it is half advertisement, half CONCEPT BOARD. (it is another fact that most of the so called finished ads are the same as well) … An adcept is to show the possible, but stripped down and miniature version of the proposed ad theme. This stage could be used for audience research to test its likeability and hence the “saleability” . It could also be used to get the Client to be in the loop and reassure him of the idea.
However a high acceptance of the Adcept does not mean that the finished ad also would be successful (as it depends on various other factors) but an Adcept is a good way of checking that the agency thinking is going in the right direction and there is no dramatic changes in mind in the clients side and agency side after having agreed the strategy and idea in the first place.
In short, Adcepts can bring territories to life, better than verbal concepts can.