"Yahoo is about making the world's daily habits inspiring and entertaining, and there are few places as inspiring and entertaining as CES," Mayer said. "We have been hard at work re-imagining Yahoo's core businesses across search, communications, media and video - all powered by two powerful platforms, Flickr and Tumblr."
Late last year, Yahoo had more than 400 million mobile monthly users for the first time in the Internet pioneer's history, according to Mayer. About 800 million people use Yahoo monthly overall, the California-based company said.
The theatrical keynote production included appearances by newly-hired Yahoo Global Anchor Katie Couric and Yahoo Tech vice president David Pogue, a former New York Times reporter.
Cecily Strong and Keenan Thompson of beloved US comedy program Saturday Night Live appeared in a faux news report skit lampooning trendy technology companies and concepts. Targets included SnapChat, Bitcoin, and in-flight smartphone use.
Grammy award-winning musician John Legend entertained the audience with a set of songs.
Announcements woven into the stage show included the launches of a Yahoo News digest app design to deliver concise, personalized summaries of global happenings twice daily to smartphones.
"Yahoo News Digest, at its core, simplifieds news and solves the problem of information overload and TL;DR," said Yahoo product manager Nick D'Aloisio, referring to an acronym for 'Too Long; Didn't Read.'
Digital magazines Yahoo Food and Yahoo Tech were launched with fanfare.
"We found our inspiration in magazines," Mayer said. "They are elegant, beautiful and have a distinctive voice."
Yahoo Food is devoted to things culinary, while the Tech magazine team headed by Pogue has a stated mission of demystifying the world of geeky gadgets, services and trends.
"Everyone at CES is a gear-head, but the rest of the country is struggling," Pogue said.
"The first language we are going to speak is called English; it's called human."
Pogue said Yahoo Tech would be a "jargon-free, cool-looking" source of news and information presented in terms people not immersed in the industry can appreciate.
And instead of banner or display ads, Yahoo digital magazines will follow the lead of their glossy predecessors and weave clearly labeled advertising into content, according to Mayer.
Pogue said he will be reviewing projects seeking backing at crowd-source funding websites Kickstarter and Indiegogo, giving as an example a stand that keeps a single razor blade sharp for five years.
"It is brilliant, but it also costs $600," Pogue said of the razor system.
Mayer mentioned the acquisition of yet another firm, Aviate, which specializes in automatically organizing applications on smartphone home screens based on clues such as location or time of day and on people's habits.
Mayer took over as Yahoo chief in July of 2012, and her plan to revive the company includes being at the center of people's Internet habits, especially on mobile devices.
"We reach for our mobile devices as soon as we wake up to check the morning headlines," Couric said, telling the audience she was eager to get to work interviewing "anyone with an important or interesting story to tell."
Digital magazines were touted as part of Yahoo's longterm strategy.
"A common theme for us is simplifying our business and how people consume information," Mayer said.
Forrester analyst David Cooperstein saw it as a savvy move to differentiate Yahoo from Google, Facebook or other online venues by providing the professional content people are looking for instead of user-generated material they might find interesting.
"It is a more mainstream play, basically," Cooperstein said.
"By bringing in familiar faces from John Legend to SNL it indicates to me she is talking about more traditional content online, which is the only angle her competitors haven't taken. And every good keynote should have some theatrics in it."
Despite many investments, Yahoo last year lost its Number 2 position in the US digital ad market to social networking titan Facebook, according to industry-tracker eMarketer.
Yahoo's share of global digital ad revenue slid about a half percent to 2.87 percent last year, while Facebook and Google say their shares rise, eMarketer reported.Stay in touch with the latest from CES 2014, via our CES page.