With so many sales and marketing books currently available, the older publications will slowly sink into obscurity. This will be a pity with anything written by David Ogilvy, who I recommend for an understanding of advertising basics.
Ogilvy wrote on a range of advertising topics, but these points are taken from his views on business-to-business sales, purchases made by companies not consumers.
An advert does not sell a product; it pre-sells it; attracts leads for you to follow up.
Adverts should promise a benefit, provide news, testimonials or information. Promise what is important to your customer. Your promise should be specific, not general.
Ogilvy stresses the importance of headlines, which receive 5 times more readers than the main body copy of the advert. But buyers read the body copy.
All goods and services can be differentiated. Even where there is a lot of competition, your advertising should still make your business stand out from the rest. Think about different advertising campaigns for different industries or niches.
And finally it’s not all down to email and the internet. Toll-free or free-phone numbers still attract the enquiries.