Advertising is a huge part of marketing. Media creation is a huge part of advertising. Photography is a large part of media product creation. Lucky industry has commercial stock photography libraries to obtain images from for your advertising campaigns, else we would all be up for some expensive photography bills. The main drawback is how long it might take to look through all the libraries.

It helps to know what sort of images you are looking for. Images can be of objects, people, flora, fauna, landscapes environments as well as actions, activity and perceptions. Each library has search tools where you can define this to reduce your searching effort. Here is one image categorisation framework that might help reduce your search time by limiting the libraries range to your specific needs:

Search categories and tags to consider…
NATURAL WORLD
Landscapes/seascapes (no evidence of human alteration)
Astronomy
Wildlife (consider also taxonomy)
Taxonomy (scientific documentation)
– flora
– fauna
– human body

NATURE-HUMAN INTEGRATED WORLD
Land & sea scapes (predominantly natural with evidence of humanisation)
Environmental concerns

HUMAN ENVIRONMENT
Settlement scenes
Travel destinations
– Iconic
– lesser known
City & metropolitan scapes
Street scenes
Industrial
Commercial
Markets, shops & trading
Architecture
Infrastructure specific

Cultural
Historic and heritage
Lifestyle & fashion
People Working
People Relaxing
Recreational focus
People Socialising
Conflict & bullying focus
People Dancing
Life events focus

Bureaucratic society & careers

Journalism
– Public sport & cultural events
– Buildup & destruction events
– News worthy documentary photography

Art for art sake
– still life
– fantasy
– surreal & altered reality
– humour

Engineered objects
– individual units (object taxonomy)
– sets

Commercial message images
– festive card images 
– Warning signs (not vector graphics)

PERCEPTIONS (storytelling themes)
– hot/cold
– summer/winter
– emotional expressions & states
– power
– freedom/persecution
– nomadic perception
– divine/evil/superhero
– alien perception

PORTRAITURE
– head & shoulders
– whole body
– whole family

Other categories might include urban/rural settings

SPECIALIST PHOTOGRAPHY
– FOOD
– REAL ESTATE
– AERIAL
– FORENSIC
– ASTRO
– WEATHER
– PHOTOJOURNALISM
– ADVERTISING