(Bloomberg)—Amazon.com Inc. promoted two senior executives to division chief executive officer positions, potentially narrowing the field of prospective successors to founder Jeff Bezos.

Jeff Wilke, 49, was named CEO of the Worldwide Consumer business, and Andy Jassy, 48, was made CEO of Amazon Web Services, the company’s cloud-computing division, Amazon said Thursday in a blog post. The promotions are meant to recognize work both men have done in building the company into a $100 billion business, and the title changes don’t represent a reorganization, said Amazon, No. 1 in the Internet Retailer 2015 Top 500 Guide.

Wilke helped expand the company’s online marketplace and Amazon Prime membership, which includes delivery discounts, and video and music streaming. Jassy was picked to run Amazon Web Services after spending two years working as Bezos’s personal confidante, a role at Amazon unofficially called the “shadow.”

This year, Amazon Web Services’ growth was highlighted in the second sentence of Bezos’s letter to Amazon shareholders, with the CEO observing that the business is on track to reach $10 billion in annual sales, “doing so at a pace even faster than Amazon achieved that milestone.”