What is a primary focus when reviewing media proposals from different vendors?

A primary focus when reviewing media proposals from different vendors is comparing CPM and pricing structures. This aspect is crucial as it directly impacts the budget allocation for media buying. By analyzing the cost per thousand impressions (CPM) and pricing structures, buyers can determine which vendor offers the best value for the target audience reach. It's essential to ensure that the proposed costs align with the campaign objectives and overall marketing strategy.

While other factors, such as evaluating creative concepts and assessing historical performance data, are significant in the media buying process, they do not directly influence the fundamental financial viability or cost-effectiveness of the media proposal as much as the pricing structures do. Additionally, understanding vendor relationships can provide insights into service quality and support but is often secondary when determining which proposal will be most effective in maximizing budget efficiency. Thus, focusing on the CPM allows media planners to make informed and strategic decisions about their media investments.