Online advertising is one of the most effective ways to reach potential new hosts and to increase awareness about Airbnb. It includes email marketing, search engine marketing (SEM), social media marketing, and display advertising. After extensive research, Airbnb has developed an internal online advertising system to expand its host base, and the number of hosts acquired through online advertising system has grown exponentially. During the system development, it found that abundant information is available about how advertising platforms such as Google and Facebook monetize with advertising, but there is only very limited information about how large marketplaces like Airbnb can fully utilize these platforms. This post provides an architectural overview of the marketing system Airbnb built and discuss the main issues that were tackled in the system. Get the full story at Airbnb