Amazon—a brand so big that the first thing that comes to mind when you hear "Amazon" is not a 2.1 million square mile land mass—makes a lot of money.

By focusing on innovation, adaptation, and customers, the erstwhile online bookseller has grown to become the e-commerce behemoth of the Internet, with a valuation nearly double those of Walmart, Macy's, and Target combined.

That's according to an infographic by Sellbrite that explores how Amazon makes money and how brands can get in on the action.

For instance, 40% of product sales on Amazon Marketplace come from third-party sellers, the graphic points out. Selling fees vary, but professional sellers can expect to pay Amazon $39.99 per month plus 10-15% for transactions. Or sellers can opt for Amazon's multichannel fulfillment to store, pack, and ship products for them.