If your ecommerce business is already successful, you may think that you don't need to advertise on Amazon. However, advertising on Amazon can help you take your business to the next level by expanding your reach, increasing your sales, and building your brand. Even if you have a loyal customer base and high organic rankings on Amazon, advertising can help you reach new customers who may not have discovered your products otherwise. Plus, advertising on Amazon can help you defend your market share against competitors who may be targeting your customers.