The revolving door at Best Buy Co. Inc.'s executive suite continued Wednesday as digital guru Stephen Gillett resigned to take a top position at antivirus software firm Symantec.

The news was a stunning twist for Best Buy, which portrayed the former Starbucks executive as a kind of technology savior when he was hired in March.

One of Gillett's major responsibilities was to redesign Best Buy's website, which is considered critical to Best Buy's efforts to improve sluggish sales. Although attracted 1 billion visits in fiscal 2012, the company converted only 1.3 percent of those visits into sales. Gillett was also charged with connecting the retailer's physical stores with its underwhelming website and mobile operations.

Given Gillett's breadth of responsibilities, his exit "looks bad for Best Buy," said David Strasser, a retail analyst with Janney Capital Management.

Gillett, a longtime executive in Silicon Valley, brought a certain buzz and big ideas to Best Buy, once telling investors he envisioned streaming price information for certain products into the stores so shoppers could compare Best Buy's prices to competitors in real time.

Now Gillett will be executive vice president and chief operating officer at Symantec, one of the country's largest makers of antivirus software. The company is also a major Best Buy vendor.

"We are grateful for Stephen's contributions during his time at Best Buy," CEO Hubert Joly said in a brief statement.

By all accounts, the two men got along. They even shared an intriguing connection: As head of Vivendi's video game unit, Joly helped develop the popular online game "World of Warcraft." Gillett is a top player of the game.

During Best Buy's investors meeting in New York last month, Joly touted Gillett's work in helping the company revive its e-commerce.

"Stephen and Hubert worked very closely crafting this strategy work," said company spokesman Matt Furman.

Since Gillett's arrival, Best Buy has seen plenty of turnover in its leadership ranks. CEO Brian Dunn resigned the following month over allegations he had an affair with a female employee. Soon after, a parade of executives left the company, including international CFO Dave Deno and chief marketing officer Barry Judge.

An outside investigation concluded that Richard Schulze, Best Buy's founder and chairman, knew of the allegations against Dunn but failed to tell the board. Schulze, Best Buy's largest investor, left the company and is now trying to buy the retailer with the help of private-equity investors. He is expected to make a bid in February.

When Joly arrived at Best Buy in September, he started to make his own moves, replacing its U.S. retail chief, chief administrative officer and chief financial officer.

Some analysts suspect Gillett started to lose influence at this time. In October, Best Buy recruited Scott Durchslag, a former Expedia president, to oversee the company's e-commerce. Soon after, the company hired Sharon McCollam as its CFO and chief administrative officer. In an interview with the Star Tribune at the time, McCollam, a former top executive at Williams-Sonoma who launched that retailer's online business, spoke mostly about one topic.

"E-commerce," she said. "Best Buy is the 11th-largest Internet retailer, but we should be much bigger than that."

Recruiting McCollam and Durchslag may have made Gillett expendable, said Strasser, the analyst. In addition to CFO, McCollam takes over IT while Durchslag, who reports directly to Joly, now oversees marketing and e-commerce.

With those two executives, "Best Buy has put together some smart ... people," Strasser said.

Furman, the company spokesperson, insisted Gillett left for what he considered a dream job at Symantec.

"This was simply an opportunity that Stephen could not pass up," Furman said.

In any case, Gillett is not walking away from Best Buy empty-handed. Although the company has not yet disclosed his compensation, Gillett owns about 344,000 share of Best Buy stock, according to documents filed with the Securities and Exchange Commission. He could not be reached for comment.

"I will miss the wonderful teams at Best Buy," Gillett wrote in a tweet Wednesday. "Our time together was short, but our friendships and experiences lifelong."

Thomas Lee • 612-673-4113