Keith said the previous management team was very good at beating up on Circuit City and smaller consumer electronics retailers, but was "fairly insular."
The new management team, Keith said, can better operate Best Buy to compete against the likes of Amazon.com, cope with the changing product cycles, and build a viable e-commerce platform, he said.
"We think those are great long-term initiatives that could drive earnings and valuation for several years," Keith said, adding that the stock is the cheapest of the 19 retailers he covers.
Credit Suisse, meanwhile, on Wednesday reinstated coverage on Best Buy with an "outperform" rating and a $30 price target, writing in a note that outsized returns in retailing happen over time in two scenarios, "management change being the primary one and acquisitions the other."
"The story today is all about management," analyst Gary Balter wrote. The analyst added that the potential earnings upside is in the $4 per share range, "implying a potential double in the stock price over a multi-year period."
But Piper Jaffray's Keith warned of challenges in the first quarter that could make it look like the turnaround is not taking hold. He cited the Super Bowl TV sales shifting into the fiscal fourth quarter, investments, and a difficult gross margin comparison.
"The numbers for Q1 probably will not be terribly exciting," Keith said.
Keith noted that while sentiment has turned bullish, Best Buy is still not a consensus "buy" on Wall Street.
"If we look at the positioning of ratings today there are 24 analysts that cover Best Buy, we now have 10 equivalent 'buy' ratings," he said. "It is by no means a consensus 'buy' from the sell side."
—By CNBC's Justin Menza