What bidding approach allows for increases or decreases in bid amounts based on specific targeting attributes?

The correct answer is bid adjustment, which is a strategy that enables advertisers to modify their bids based on various specific targeting attributes such as device type, location, time of day, or audience characteristics. This flexibility allows marketers to optimize their campaigns by setting higher bids for segments that are more likely to convert and lower bids for those that are less effective.

With bid adjustment, advertisers can fine-tune their approach to reach the most relevant audience, ensuring that they maximize the return on their advertising spend. For instance, if data analysis shows that mobile users are more likely to convert, a marketer may choose to increase their bid for mobile traffic while decreasing it for desktop users.

The other options, though related to bidding strategies, do not provide the same level of specificity in targeting adjustments. Cost-per-click bidding is a basic payment model where advertisers pay for each click, without adjustments based on targeting attributes. Target return bidding focuses on achieving specific return goals rather than adjusting bids dynamically based on audience specifics. Enhanced CPC bidding combines manual bidding with automatized adjustments but does not allow for the direct, granular targeting adjustments that bid adjustments facilitate.