3. The method of claim 1 , wherein executing the first application program in response to detecting selection of the electronic message includes displaying an object on the display.
1. A method, comprising: at a computer with a processor and a display: receiving an electronic message that is sent over a network, the electronic message including a body of text including one or more words to be displayed to a receiving user, and a first portion of a first application program, the first application program including functionality for displaying advertisements on the display; after receiving the electronic message, detecting selection of the electronic message; and, in response to detecting selection of the electronic message: opening the electronic message, displaying the body of text on the display, and executing the first portion of the first application program, which calls a second portion of the first application program using as a parameter at least a portion of the one or more words displayed to the receiving user, the second portion of the first application program being located at a site on the network that is remote from the computer, thereby retrieving an advertisement and displaying the advertisement on the display.