Robinson,H . "Internet advertising effectiveness: the effect of design for click-through rates for banner ads" International journal of advertising [0265-0487] 26.4 (2007). 527-541.

    This empirical study investigates characteristics of banner ads and the role they play on online advertising effectiveness in the world of online gambling. The relationships between the click-through-rate (CTR) and seven design elements (banner size, message length, promotional incentive, animation, action phrase, company brand/logo and casino games) are examined, and although the author states up front that that the intention of the study is to see how these relationships differ between the online gambling industry and other e-commerce, this information can still be rendered useful. The study found design elements of effective banner advertisements include: “a larger size, long message, absence of promotional incentives and the presence of information about casino games.” The company/brand logo was found to be an “ineffective characteristic” in attracting a direct response.
    While it would not be accurate to generalize this data to all banner advertisements, the authors do say, “these results also suggest that the effectiveness of banner ad campaigns for online gaming (as measured by CTR) is governed by the same principles of artistic execution as those found in other, non-gambling-related sectors of the internet.” The inability of click-through rates to assess other effects such as emotion (which an ad evokes) or memory (of a particular brand on an ad) seems to be magnified in this study, for it is heavily based around the already faulty click through rates. Specifically, the finding that the brand logo is an ineffective characteristic in attracting a direct response seemed troubling at first because brands and logos play a major role in eliciting credibility. However, credibility can still be present, even if it is not evidenced by a click through (possibly a limitation of this study)