noun
advertising agency business
Refers to the industry or business of advertising agencies, including planning, creating, and placing advertisements.
彼は広告代理業に長年携わっている。
He has been in the advertising agency business for many years.
広告代理店 refers to an advertising agency as a company or office, while 広告代理業 refers to the business or industry itself.
Compound of 広告 (advertisement), 代理 (agency, representation), and 業 (business, industry).