Illustration ads and photography ads

What do you guys think the differences between illustration ads and photography ads? Some people may say that illustration ads are more abstract and photography ad are more concrete. Some people may say that illustration ads are more approach to express a concepts rather than a specific product.

However in the current advertisement industry, the ad agency would concern about more about their cost, because photography ads usually more expensive than illustration ads. They usually make a decision by how much money would their client pay for them. If their clients inject less money for making their ads, then   illustration ads are the better choice, because to draw several pieces of illustration is fast and economy way. In addition, those illustrations that contain some symbols and graphics are a kind of stronger visual language that most photography cannot compete with.

Photography are consider as a common way of making ad. Although to making a photography cost a lot of money to rent s studio hair a bunch of people such as photographers, photographers assistances, gaffers, talents, or cosmeticians etc, there still 90 % of Ads in the market are photography. Because real image are more explicit and more direct way to selling their products, and real image has less possibility to confuse audience. When people see a real image, they would spend more time to reading the image rather than reading the headlines. So that a efficient way to target people.