Direct marketing involves sending targeted marketing materials like catalogs and mailers directly to consumers to promote products and services. It relies on databases of customer information and contact details to address specific marketing messages to audiences. The key benefits are targeting customized messages, affordability, and measurability of responses. However, challenges include the risk of annoying customers with intrusive tactics, low response rates, and potential legal issues around privacy and data protection. Some also see direct marketing practices as unfairly taking advantage of customers or invading their privacy in some cases.