Advertising agencies fall into two broad categories – full service agencies and specialized agencies. Full service agencies offer a complete range of advertising-related services across all media and all market sectors. Specialized agencies fall into three further categories – independent agencies offering a limited range of services such as media buying, agencies focusing on specific media such as Internet advertising, and agencies working in a narrow market sector such as business-to-business advertising.


Media buying agencies, also known as media independents, act as agents for advertisers or other advertising agencies. They offer detailed knowledge of media and can offer their clients the benefits of scale, using their buying power to obtain favorable rates from media owners. Creative agencies also offer a limited range of services, concentrating on the creative aspects of advertising. They may work in partnership with larger agencies with limited creative resources or they may take on special projects for other agencies where a campaign requires specific skills.


Business-to-business advertising agencies handle advertising for clients marketing business products or services to other businesses. The marketing process is more complex than consumer marketing with longer sales cycles, higher-value products and larger decision-making groups. Within the business-to-business category, agencies may offer further specializations in sectors such as technology or financial services. Corporate advertising agencies promote organizations, rather than products or services. Their role is to build a positive reputation for clients by communicating corporate and financial performance to investors, analysts, customers, politicians and other stakeholders.


Public service agencies create advertising campaigns for government departments. Their role is to raise public awareness of issues such as health or the environment, or to communicate information about government services.


Recruitment agencies specialize in recruiting and selecting candidates for job vacancies on behalf of clients. Some offer recruitment expertise in specific sectors such as accountancy or information technology. Others may specialize in different job levels such as executive search or freelance and contract workers.


Digital agencies, also known as new media agencies, develop advertising campaigns for the Internet and other digital media. They produce banner advertising, viral campaigns and email marketing, as well as campaigns in other media such as mobile advertising and video. Digital agencies offer specific technical skills in the use of digital media, as well as traditional advertising services such as planning and media buying.


Social media agencies form a subset of new media agencies. They concentrate on using social media such as Facebook, Twitter and blogs to communicate with consumers and business customers. In addition to helping clients use social media, agencies also monitor social networks to respond to any threats to their clients’ reputations.


Integrated agencies offer the equivalent of a full service agency, but claim to integrate communications to achieve improved campaign results for clients. By using techniques such as advertising, email and social media to reinforce each other in a single campaign, integrated agencies aim to improve response and conversion rates while reducing overall campaign costs.