What is the primary disadvantage of focusing exclusively on keywords with high search volume when creating an initial campaign?

The primary disadvantage of focusing exclusively on keywords with high search volume when creating an initial campaign is increased competition and higher costs without necessarily guaranteeing a higher conversion rate or ROI. High search volume keywords are typically very broad and attract a wide range of users, many of whom may not be actively seeking to purchase a product or service. This leads to increased competition from other advertisers targeting the same keywords, driving up the cost per click (CPC) and cost per acquisition (CPA). Furthermore, because the intent behind these broad keywords can be varied, the traffic generated may be less qualified, resulting in a lower conversion rate. For example, a keyword like 'shoes' has a very high search volume, but users searching for 'shoes' could be looking for anything from athletic shoes to dress shoes to shoe repair services. Targeting this keyword without further refinement will likely result in a lot of wasted ad spend on clicks from users who are not interested in the specific type of shoes you sell. Long-tail keywords, which are longer and more specific phrases, often have lower search volumes but can be more effective at attracting qualified traffic with a higher conversion rate. Focusing exclusively on high-volume keywords at the outset can lead to inefficient spending and a lower overall ROI compared to a more targeted approach that incorporates a mix of high-volume and long-tail keywords.