<P> Barratt introduced many of the crucial ideas that lie behind successful advertising and these were widely circulated in his day . He constantly stressed the importance of a strong and exclusive brand image for Pears and of emphasizing the product's availability through saturation campaigns . He also understood the importance of constantly reevaluating the market for changing tastes and mores, stating in 1907 that "tastes change, fashions change, and the advertiser has to change with them . An idea that was effective a generation ago would fall flat, stale, and unprofitable if presented to the public today . Not that the idea of today is always better than the older idea, but it is different--it hits the present taste ." </P> <P> As the economy expanded across the world during the 19th century, advertising grew alongside . In the United States, the success of this advertising format eventually led to the growth of mail - order advertising . </P> <Table> <Tr> <Td> </Td> <Td> This section's factual accuracy is disputed . Relevant discussion may be found on Talk: Advertising . Please help to ensure that disputed statements are reliably sourced . (May 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section's factual accuracy is disputed . Relevant discussion may be found on Talk: Advertising . Please help to ensure that disputed statements are reliably sourced . (May 2016) (Learn how and when to remove this template message) </Td> </Tr>

What are the two forms of advertisement that a brokerage is involved in