A system may present dynamic content to an e-mail recipient in the form of an image implementing frame-sequence animation. Each frame may present an offer to the recipient. Upon selection of an offer, the system may determine which offer the recipient selected by determining which frame was displayed when the recipient responded. The e-mail may include an image URI specifying a frame-sequence animation image. The image URI may include an identifier, which may allow the system to determine when the recipient opened the e-mail message, and a link URI, which may also include the identifier. When the recipient indicates a response to an offer, the system may associate the link URI with the image URI and may determine to which offer the recipient was responding.