Direct marketing agencies used to have a much more straightforward role. Direct mail used to primarily consist of mail outs. Today, direct marketing includes a variety of media such as televised infomercials, door-to-door selling, newspaper inserts, telemarketing plans, counter cards, and package inserts.
As opposed to regular advertising, in direct marketing, the customer is specifically targeted for a reason. The agency will select people from a database or other channels and they will receive the promotion directly. As opposed to magazine ads and billboards which target a more general population.
You can hire a direct marketing agency to handle this for you. The agency will build the lists, do market research, and come up with creative ideas that target your brand to your best customer. IN the campaign the agency will build a way to track how the customer gets back to you, whether through a direct response, coupon code, or other ways. This makes it easier to measure than other forms of advertising.
They also offer services such as finding new leads, drive people to site, mailing list strategies, and customer retention.
When considering a direct marketing agency, you need to know what their philosophy is, how they can measure success for you, and their expertise in various channels.