Web-only retailer Overstock.com Inc. is splitting the post of chairman and CEO, with company founder Patrick Byrne remaining CEO and handing the chairman job to Jonathan Johnson, a long-time company executive. Overstock also announced that Stormy Simon, who has held the post of co-president with David Nielsen since February 2013, has been promoted to president.

“I have long maintained that, simply as a matter of good institutional design, the roles of chairman and CEO should be split,” Byrne says. “Now is the right time for Jonathan to assume the position of chairman, for which he has been in preparation for so long.” Johnson has been executive vice chairman since May 2013. He joined Overstock in 2002 as general counsel and served as company president for five years.

Simon started as a temporary worker 12 years ago, but quickly became a key employee at Overstock, says CEO Patrick Byrne. She directed the company’s marketing team for three years and also headed up customer service. Most recently, she managed the supply chain, warehouse, international and human resources departments. “Most importantly, Stormy is an empath who, like Star Trek’s Deanna Troi, wanders through our organization psychically tuning it up wherever it is needed,” Byrne says. “I am just along for Stormy’s ride.”

Overstock reports it increased sales in 2013 by 18.6% year over year, to $1.304 billion from $1.099 billion. It attributes much of that growth to a 17% increase in average order size: In 2013, costumers spent an average of $158 per order, compared with $135 in 2012. Gross profits also increased 24.8%, to $247.7 million from $198.4 million last year, the retailer says.

Overstock is No. 31 in the Internet Retailer Top 500 Guide.