Marissa Mayer 'Balked' at Hiring Gwyneth Paltrow for Yahoo Food Because She Didn't Graduate From College In developing Yahoo's myriad tech products, Mayer obsessively references data and metrics. In honing the company's media strategies, however, she prefers to go with her gut.

The best leaders are able to tread a tricky balance between reason and instinct. But for Yahoo's Marissa Mayer, these governing principles tend to be uniquely compartmentalized.

When it comes to developing Yahoo's apps, digital services and other tech products, the Google-reared Mayer is obsessive about data, surveys and metrics, according to a new tell-all by Nicholas Carlson entitled Marissa Mayer and the Fight to Save Yahoo! But in honing the company's media strategy, Mayer prefers to go with her gut.

For instance, the fact that she is a Saturday Night Live super fan likely impacted Yahoo's decision to purchase the show's archives in April 2013 for $10 million, writes Carlson, chief correspondent at Business Insider.

Related: Marissa Mayer: Privacy Fanatics Will Have a Less Awesome Life Online

And colleagues occasionally questioned Mayer's myopic tastes. "There was a fear," according to Carlson, "that Mayer, who preferred to read Town and Country and wear Oscar de la Renta couture, might undermine the company's middle-American brand."

But most interesting of all, perhaps, was a curious bias that pervaded Mayer's hiring processes. Namely, she "balked" at bringing Gwyneth Paltrow onboard as a contributing editor at Yahoo Food -- despite the fact that Paltrow had a best-selling cookbook and was the creator of a popular lifestyle blog, Goop -- simply because she hadn't graduated from college.

Mayer, a Stanford alumnus, "habitually asked deputies where they attended college," according to Carlson.

We've written before about the ways in which curating a unanimously like-minded team -- a pervasive notion in Silicon Valley -- can quickly veer into discrimination. It's also bad for business.

Related: Why Peter Thiel's Philosophy on Hiring Is Hurting Silicon Valley

And while it's doubtful that Paltrow would have singlehandedly saved Yahoo, Carlson notes another celebrity hire in which Mayer's impulses led her astray. At an ad conference in the Turks and Caicos, she decided to ink a deal with Katie Couric -- despite the fact that Couric was already the host of a hugely unsuccessful Yahoo video series entitled Katie's Take.

"Mayer ignored those metrics, and in mid-2013, she named Couric Yahoo's "global anchor' in a deal worth more than $US5 million a year," Carlson writes.

To this day, despite several high-profile interviews, Yahoo users still aren't clicking on Couric's videos.

Related: Marissa Explains It All: 5 Motivating Quotes From Yahoo's CEO