Retailer Best Buy Co. has appointed Sharon McCollam CFO and chief administrative officer, effective December 10. Earlier this year, she retired from Williams-Sonoma Inc., where she was CFO, chief operating officer, and a director of the company. As CFO, she replaces James Muehlbauer, who said in October that he was leaving the firm.

Zynga Inc. has promoted Mark Vranesh to the top finance spot. Vranesh, currently chief accounting officer, had formerly led finance at the social-game services provider from 2008 until 2010. He takes over from David Wehner, who is taking a “senior finance position” at Facebook.

Subject to regulatory approval, Donald Colvin has been named to lead the finance function at Caesars Entertainment Corp. Previously, he was CFO of ON Semiconductor Corp.

Dennis Secor has been named CFO and treasurer of Fossil Inc., effective December 10. He takes over from Mike Kovar, who is retiring from the firm in March but will step down as CFO and treasurer on December 10. Secor joins the company from Guess Inc., where he heads finance.

Finance chief Jerry Elliott has been promoted to president and chief operating officer of LeapWireless International Inc. Elliott, who has been at the company since May, will be succeeded as finance chief by Perley McBride, effective December 10. McBride is a former executive vice president of finance at The Weather Co.

Michael Schradle has been appointed CFO and senior vice president of finance at Adept Technology Inc. Most recently, he headed finance at Liquid Robotics Inc.

Brendan Connors has resigned as finance chief of weight-loss product manufacturer Medifast Inc. Senior controller Edward Powers will serve as interim CFO until a permanent replacement for Connors is found.

Boingo Wireless Inc. has promoted Peter Hovenier to lead the finance function. Hovenier, who joined the company in 2002, had been senior vice president of finance and administration.