What is an effective method to prevent Standard Shopping ads from showing at unwanted times?

Adding negative keywords in the campaign settings is effective in preventing Standard Shopping ads from showing at unwanted times because it allows advertisers to specify terms that should not trigger their ads. By strategically selecting negative keywords, businesses can filter out irrelevant searches that do not align with their target audience or product offerings. This not only helps in conserving budget by avoiding clicks from users who are less likely to convert, but also ensures that ads are displayed only during relevant searches.

In contrast, the other options might not effectively control unwanted ad visibility. For instance, adding negative keywords in the product feed could have limited impact if not properly integrated, and adjusting keyword bids in Merchant Center primarily affects where ads appear rather than when they appear. While audience targeting adjustments can refine who sees the ads based on demographics or behavior, they may still not provide the granularity needed to eliminate unwanted search triggers. Thus, using negative keywords at the campaign level remains a straightforward and impactful approach to manage when Standard Shopping ads are shown.