The buyer/planner notices significant budget underpacing for a self-serve programmatic display campaign. What is the MOST LIKELY reason for this?

The observation of significant budget underpacing in a self-serve programmatic display campaign often indicates that the bids being set are too low to compete effectively in the advertising auction. In programmatic advertising, bids determine the likelihood of ad impressions being won; if the bids are below the competitive threshold for the selected inventory, the campaign will underdeliver relative to its budget.

When the bidding strategy is ineffective, even with an available budget, the campaign may not receive the expected impressions or clicks, leading to underpacing. Higher bids generally enable better chances of ad placements, thus utilizing the allocated budget more efficiently.

In contrast, while creative assets being unapproved could impact the execution of the campaign, it would not explain underpacing relative to the budget already set. Similarly, targeting being too broad would likely result in high spend but potential inefficiency in reaching the target audience. Lastly, a short campaign duration might limit the total budget expenditure but does not directly correlate with pacing underutilization unless all other factors suggested a full burn, which is unlikely without adequate bidding.