Embodiments of the invention provide ways to update and permit third-party advertising content of a webpage developed using Asynchronous JavaScript and XML (“AJAX”) techniques. An illustrative method includes registering a set of possible triggering events that can invoke an advertisement-update process, registering advertisement containers (portions of the webpage that can present the advertisements), receiving an indication that a triggering event has occurred, identifying (in some cases) advertisement containers whose advertisement content is to be updated, accessing third-party advertisement data that is stored outside of the domain of the webpage to receive the fresh advertising content, and presenting the fresh advertising content in the one or more advertisement containers.