The purpose of this research is to determine whether optimal ad placement and page context can significantly impact advertising effects, by extending hemispheric processing theory. This study contributes to the marketing literature by 1) addressing theoretical conflicts regarding optimal hemispheric ad placement (more favorable effects with leftward photo ads and rightward text ads; Janiszewski 1988) and page context (matching activation from "priming" of opposing brain hemispheres Janiszewski 1990), 2) by evaluating multiple advertising effects in relation to mere exposure rather than focusing primarily on attitudes (Janiszewski 1988, 1990), and 3) by addressing an important knowledge gap regarding optimal Web advertising (Dahlen, Rasch and Rosengren 2003). A growing amount of money is being spent on Internet advertising, with revenues totaling $12.5 billion in 2005, up more than 30 percent over 2004 (IAB 2006). However, banner ad click-through rates are low (between .1 and .2 percent for standard ads; DoubleClick 2007) and only 10% of business executives believe that banner advertising is highly effective in generating new business (Forrester 2006). Advertisers continue to use banner ads, perhaps because the "branding" benefits are not limited to clickthroughs (Briggs and Hollis 1997). While numerous ad-related factors have been previously studied (e.g., ad context creative factors, recall/recognition effects, repetition), to the author's knowledge no research has examined the effect of banner ad placement on advertising outcomes such as attention, recognition, brand attitude and purchase intention. / A 2 x 2 x 2 between subjects factorial design was implemented, in which the ad type (pictorial or verbal), ad placement (left or right of Web page), and the page type (text or image-oriented) were manipulated in an online environment. While the results only partially support the hypotheses (rank-ordered stimuli groups from "optimal" to "least optimal" effects) matching activation and hemispheric ad placement appeared to differentially affect advertising outcomes. A supplementary data analysis, which directly compared hemispheric ad placement and matching activation, indicates that matching activation has a greater effect on attention, while hemispheric ad placement has a greater effect on purchase intention. The findings suggest that online advertising efforts should be specifically matched with advertising goals. Managerial implications are discussed. / by Kendall Goodrich. / University Library's copy lacks signatures of Supervisory Committee. / Thesis (Ph.D.)--Florida Atlantic University, 2007. / Includes bibliography. / Electronic reproduction. Boca Raton, FL : 2007 Mode of access: World Wide Web.