Mayer has already spruced up Yahoo's front page, email and Flickr photo-sharing service, as well as engineered a series of acquisitions aimed at attracting more traffic on mobile devices. The shopping spree has been highlighted by Yahoo's $1.1 billion purchase of Tumblr, an Internet blogging service where the company rolled out its new logo.
The redesigned logo retains some of the elements of the old one, including the company's official color, purple. Yahoo's familiar exclamation point, meant to punctuate a yodeling sound that has long been the company's calling card, is still there, too, but with a twist. When visitors come to Yahoo's front page or an app, the exclamation point dances across some of the lettering before settling at the end of the company's name at a slight tilt of 9 degrees.
"We knew we wanted a logo that reflected Yahoo -- whimsical, yet sophisticated," Mayer wrote on her Tumblr account. She hailed the redesigned looks as "modern and fresh, with a nod to our history. Having a human touch, personal. Proud."
Mayer, 38, said she spent most of one weekend this summer figuring out what the new logo should look like with four other Yahoo colleagues: Bob Stohrer, Marc DeBartolomeis, Russ Khaydarov, and an intern, Max Ma.
In an effort to drum up more interest in the changeover, Yahoo spent the past 30 days showing some of the proposed logos that Mayer and her helpers cast aside.
Reaction online was swift and at brutal after the new look was unveiled late Wednesday night.
"Sooooo ugly!!" blasted @JakeTMG on Twitter. "Oh my god!! It looks even worse than their old logo! @Yahoo this is disgusting."
Posters took the new style to task for its "ugly 3-D effect," being "derivative and bland," and being a shoddy final choice after being subjected to the company's "30 days of change" campaign, which showcased a new logo idea every day for the past month.
But there were fans.
Some of those who took to social media called it "clean and elegant," others "skinny and neat."
The revision is the first time that Yahoo has made a significant change to its logo since a few tweaks shortly after co-founders Jerry Yang and David Filo incorporated the company in 1995.
Since Yahoo's logo is so recognizable, it's a good thing they kept the changes relatively sedate, says branding expert Laura Ries, of the Atlanta firm Ries & Ries.
"One of the worst things in the world you can do is have a log around for two decades and then do something totally different. It's quite unsettling for consumers," she said. Keeping the purple and the exclamation point was a good idea, she said.
Mayer's overhaul of Yahoo has attracted a lot of attention, but so far it hasn't provided a significant lift to the company's revenue. Yahoo depends on Internet advertising to make most of its money, an area where the company's growth has been anemic while more marketing dollars flow to rivals such as Google and Facebook.
A new logo is an important part of updating Yahoo, Ries said, but at the end of the day the company has to do a better job of "verbalizing what exactly Yahoo is."
Staff writer Eric Kurhi contributed to this story.