Under the terms of the agreement, Amazon (AMZN) will receive a 16.6 percent stake in Ashford.com (ASFD) for the investment, and will run the marketing on the Amazon.com site through next year's holiday season.

Diamonds, watches, sunglasses, and writing instruments are among the new products in the luxury category. The selection represents more than 300 brands, such as TAG Heuer, Omega, and Montblanc, Lambertson Truex, Lisa Jenks, and Killer Loop.

The purchase plays into Amazon's goal of becoming the online superstore, with its game plan to offer shoppers whatever they desire in one centralized portal. The company currently lists more than 18 million items ranging from its original play of books to CDs, toys, electronics, videos, DVDs, home-improvement products, software, and video games.

Amazon.com Tuesday continued to expand its product offerings with the acquisition of Back to Basics Toys, a leading online retailer specializing in rare, classic toys.

Last month, it divided its site into four stores -- home improvement, software, gift ideas, and video games --as part of the one-stop shopping destination strategy. Amazon also bought Tool Crib of the North, a leading tools and equipment catalog company.

Investors have staged a lukewarm response to many of the new deals, evidence of lingering doubt in Amazon's preference to build its product line over the goal of making a profit.