NEW YORK ( TheStreet) -- Yahoo!'s ( YHOO) first-quarter earnings beat Wall Street estimates, but some of the shine is off CEO Marissa Mayer as the core of the business continues to take a long time to turn around.

Yahoo! reported first-quarter non-GAAP earnings of 38 cents per share on $1.14 billion in revenue, excluding traffic acquisition costs. Including TAC, sales were $1.07 billion, missing estimates. Analysts polled by Thomson Reuters expected Yahoo! to earn 24 cents per share on $1.099 billion in revenue for the first quarter.

The company noted display revenue ex-TAC was $409 million for the first quarter of 2013, down 11% year-over-year. Search revenue ex-TAC was up 6% year-over-ear to $402 million, but price-per-click (PPC) fell 7% annually, as mobile ads continue to monetize at a weaker rate than desktop.

Mayer noted that Yahoo! is really positioned well to take advantage from the growth in mobile, particularly tablets. Poor monetization from mobile, however, isn't demonstrating Yahoo!'s strengths right now. As such, investors remain in a wait-and-see mode, says UBS analyst Eric Sheridan. "We remain skeptical that investors willsee an inflection in the core business (especially pricing of Display & Search products) in the medium term," Sheridan wrote in his note. He rates shares "buy" with a $27 price target.

Now is the time where recent acquisitions such as Summly, Jybe, Snip.It and Alike start to pay off. Mayer has talked about mobile and personalization as two of Yahoo!'s keys to its future. We saw a little of what Summly had to offer last night, as it condensed Mayer's 2,000 word earnings script into 140 words.

The company's search deal with Microsoft ( MSFT), which ended in March, is still a work in progress. "There was still a gap in monetization and we will work with Microsoft to improve our search monetization," Mayer said on the call.

Mayer asserted that Yahoo! is best positioned in the industry because it is able to partner with other heavyweights such as Apple ( AAPL), Google ( GOOG), Facebook ( FB) and Microsoft. "Partnerships is a huge differentiator for Yahoo!," Mayer said on the call. "We want to put our users first and make their daily routines truly delightful."

It's nice to have these partnerships, but eventually, Yahoo! has to see something out of them, aside from just getting the company's name out there. Mayer was asked about the weather app on Apple's iOS and if there was anything more to be done with that, and she pointed to the fact that the Ybing (the little oval on the left hand side of the app that is Yahoo!'s logo) is helping people familiarize themselves with Yahoo!'s offerings.

Yahoo! has over 700 million monthly users. By now, you would think they know what Yahoo! has to offer.

Outside of Yahoo!'s valuable Asian assets, (its 24% stake in Alibaba and 35% stake in Yahoo! Japan), core Yahoo! (search and display) has been stagnant, but Mayer is working to change that. The company is no longer the laughing stock of Silicon Valley and has been able to acquire and retain some top engineering talent.

Her plan is going to take some time to come to fruition, as second-quarter guidance was weaker than estimates. Excluding TAC, revenue is expected to be between $1.06 billion and $1.09 billion. Analysts polled by Thomson Reuters are looking for $1.12 billion in sales.

We got a little sneak peek of her plan as she said she expects Yahoo! to update its products and announce new ones faster than it had previously. "So in terms of the next sprint, this is really the fun part," Mayer said on the call. "So I really think what you're going to see is that Yahoo!'s products will be releasing with small changes much more frequently and there'll even be what I would call version update, much more frequently, particularly on mobile and on the Web site."

Credit Suisse analyst Stephen Ju, who rates shares "neutral," noted that Yahoo! "remains a work in progress," as Mayer continues to share her vision, albeit a broad one for turning the company around. "Similar to prior quarters' reports, CEO Marissa Mayer outlined a broad strategy with focus on mobile, personalization as well as the re-imagining of its search and display businesses, although a specific product roadmap was not yet delineated," Ju wrote in his note. "As such we remain in a wait-and-see mode pending further signals of a meaningful turnaround."

The honeymoon period for Mayer is over as she comes up on her one-year anniversary at the helm of Yahoo! She has changed the perception of the company, raised the stock price and given investors hope. Now it's up to her and her team to execute on the plan, however broad it is.

-- Written by Chris Ciaccia in New York

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