Final answer:
Direct mail advertising is sent directly to prospective customers using mail services, addressing the advertising downturn faced by traditional media channels.
Step-by-step explanation:
The forms of advertising that are sent directly to prospective customers through a private, electronic, or government mail delivery service are commonly referred to as direct mail advertising. As technology has advanced, traditional advertising channels such as television and print media have become less effective, leading to a decline in advertising revenue. Companies are exploring new ways to reach consumers directly, and direct mail represents one such method that bypasses the challenges posed by the ability of consumers to skip through traditional ads.