A study done by ContextWeb and Online Text Exchange found that ads placed contextually at the page level outperformed (in terms of branded recognition and ad recognition) both ads placed without regard to context, and ads placed contextually at the site level .
It shouldn’t come as a surprise that contextual ads (for instance, Dell or Intel ads embedded in an article on computers) outperform those embedded on a neutral page—reading an article on a specific topic demonstrates familiarity and affinity for the subject matter, so one would assume there is both greater recognition of the advertiser and intelligibility and appreciation for the proposition of the branded message among readers of specific topics.
What is surprising is that context-matching at the page level outperforms the same context-matching at the site level. Is it possible that on a niche site too many similar products drown each other out and dilute the strength of any specific brand’s message? On a site dedicated to computers, it might be easy to forget which manufacturer is offering a $500 rebate on laptops, because visitors were exposed to ads from Dell, Compaq, Gateway, Sony and Lenovo, for example.
In contrast, a general news site with only one tech feature might only feature one ad showcasing laptops, so its relative uniqueness among the pack might be retained better by the reader.
At any rate, the study seems to strengthen the argument that advertisers might be better served by spreading their spend more broadly, allowing contextual matching technology to serve their specific message/offer on pages that are topically similar, rather than concentrating on a narrower band of niche sites that more closely align with their product category.