The results made Bain a top-tier brand and Romney wealthy.
Bain Capital invested about $2.5 million in the early days of Staples. The first store opened in 1986 and, when the chain went public three years later, Bain pulled in $13 million. Bain turned a $5 million investment in Accuride's tire rim line into a $121 million boon.
But there were failures, too. Bain lost most of its $2.1 million investment in a bathroom fixture company and saw a handbag company fail after a $4 million investment.
When choosing employees, Romney's team put applicants through a series of questions designed to test quick thinking and critical analysis.
What is the revenue of a London music festival? How can Bain help a European airline turn around its declining profits? What would an applicant do if he didn't get a second interview?
It wasn't that the interviewers expected applicants to know how many taxis were actually in New York City. Rather, they wanted to see how the applicant would figure out an answer on the fly.
"We're talking very analytical attention to details, we're talking about a deep dive into the operations of a company," said Howard Anderson, a senior lecturer at MIT's Sloan School of Management who has studied both Bain and Romney. "By the time Bain makes an investment, they know more about the company than the company knows about itself."
Romney will end up knowing just as much about his running mate.
He has spent a considerable amount of time studying the benefits and drawbacks of potential candidates such as Rubio, Ohio Sen. Rob Portman and New Hampshire Sen. Kelly Ayotte. Others who may be in the mix include New Jersey Gov. Chris Christie, former Florida Gov. Jeb Bush, Rep. Paul Ryan of Wisconsin and Virginia Gov. Bob McDonnell.
Data and research are driving the weeding-out process for the rest. Tough interviews with Romney are all but certain to follow for those who make the cut.
"My criteria is: Who can be president if that were necessary?" Romney told the Des Moines Register this week.
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