Final answer:
Keyword targeting should be avoided when dealing with a news publisher that constantly refreshes the text on their page, as the volatility of the content makes it unreliable to depend on specific keywords for accurate ad targeting.
Step-by-step explanation:
When targeting a private deal with a news publisher that constantly refreshes the text on the page, it is important to consider the dynamic nature of the content in choosing the appropriate targeting method. Among the options listed, Keyword targeting should be avoided because this type of targeting relies on specific words or phrases to be present on the website's content. Since the text is constantly changing, the chosen keywords may not always be relevant, potentially leading to missed opportunities or inaccurate targeting.
In contrast, Contextual targeting might still be useful if the overall theme or category of the content remains constant despite text changes, as it focuses on the context of the page rather than specific keywords. Geo-targeting and Demographic targeting are unaffected by the changing text as they focus on the location and attributes of the audience respectively, rather than the content itself.
Therefore, the mentioned correct option in the final answer to avoid when dealing with constantly updating text content is a) Keyword targeting. To summarize, while choosing only one option, the most effective approach when dealing with rapidly changing content is to utilize targeting methods that do not solely depend on the presence of specific words or phrases. Thus, other forms of targeting should be considered to ensure consistent and accurate delivery of ads in such environments.