Olga has several line items under her campaign. Two of the line items are underdelivering and not meeting performance goals, while two are high-performing. Which of the following is the recommended optimization strategy?

The recommended optimization strategy is to shift budget from underperforming line items to high-performing ones. This allows the budget to be reallocated to areas that are already demonstrating success and efficiently meeting performance goals, maximizing overall campaign effectiveness. Shifting budget from high-performing to underperforming line items is counterproductive, as it reduces investment in what is working. Adjusting frequency caps to serve more impressions on underperforming line items might further waste budget if the targeting or creative is ineffective. Conversely, serving fewer impressions on underperforming line items doesn't address the core issue of poor performance and simply reduces their activity without improving efficiency.