Describe a scenario in which device-specific bidding adjustments would hinder rather than enhance campaign performance.

A scenario in which device-specific bidding adjustments would hinder rather than enhance campaign performance occurs when the attribution model being used does not accurately reflect the cross-device customer journey, leading to inaccurate assessment of device performance. Device-specific bidding adjustments allow advertisers to increase or decrease bids based on the type of device a user is using (e.g., desktop, tablet, mobile). The intent is to optimize bids based on the perceived value of traffic from each device. However, if a customer interacts with an ad on a mobile device but completes the conversion later on a desktop computer, a last-click attribution model would attribute the conversion solely to the desktop interaction, underrepresenting the value of the initial mobile interaction. In this case, if the advertiser decreases bids for mobile devices based on the falsely low conversion data from last-click attribution, they would be hindering campaign performance by reducing visibility on a device that plays a crucial role in the initial stages of the customer journey. This is particularly relevant for products or services that involve research on mobile devices followed by a purchase on a desktop, or vice versa. Using a more sophisticated attribution model that accounts for cross-device conversions, such as a linear or time-decay model, is essential to accurately assess the true value of each device and make informed bidding adjustments. Therefore, incorrect attribution can lead to misinterpreting device performance and making bidding adjustments that negatively impact overall campaign effectiveness.