Advertising your books on Amazon can be an effective way to reach a large audience of potential readers and increase your book sales.

Here are some reasons why:

1. Massive audience: Amazon is the largest online bookseller in the world, with 350 million customers visiting the site regularly. This means that your book will be exposed to a massive audience of potential readers.
2. Targeted advertising: Amazon's advertising platform allows you to target specific audiences based on their browsing and purchasing behavior, as well as their interests and demographics. (This means that you can reach readers who are most likely to be interested in your book.)
3. Increased visibility: By advertising on Amazon, your book will be more visible to potential readers. It will appear higher in search results, be featured on relevant product pages, and appear in targeted ads.
4. Cost-effective: Amazon's CPC (cost per click) advertising platform is cost-effective, as you only pay when someone clicks on your ad. You can also set a budget for your campaign, ensuring that you don't overspend.
5. Metrics and data: Amazon's advertising platform provides detailed metrics and data about your campaign's performance, including impressions, clicks, and conversions and ACOS (average cost of sale). This information can help you refine your advertising strategy and optimize the campaigns for better results.

Overall, advertising your books on Amazon can be a great way to reach a large and targeted audience of potential readers, increase your book sales, and gain valuable insights about your readers.