An system and method for enabling an individual to pretest stimulus alternatives, by carrying out eye-tracking experiments on a subject with a digital camera, a personal computer and webcam, or a camera built into a laptop, tablet, smart phone, or other mobile device. The method of implementing the invention may be based on use of the internet for transmitting experimental stimuli, data, and / or results. The method enables the practitioner to determine which of two or more competing stimulus images, displayed at the same time, draws more spontaneous gaze direction from the subject during the first few moments of exposure. The method enables one to express the result as a ratio or other comparative index.