Nothing is so important to the long-term Yahoo! (NASDAQ: YHOO) earnings story as mobile apps, Fool contributor Tim Beyers says in the following video.

How do we know? CEO Marissa Mayer makes it a point to highlight the company's mobile numbers every quarter. In Q4, roughly 400 million were using Yahoo! mobile apps monthly. In Q1, that number rose to 430 million.

In a call with analysts, Mayer described Yahoo! as a "mobile first" company with four areas of emphasis across its entire business: search, communications, digital magazines, and video, with Flickr and Tumblr backstopping each effort.

But it's mobile that Mayer sees driving the business. Total display ads sold rose 7% in the first quarter, and according to Mayer, success with mobile is partially responsible for the gain. She cited higher traffic traffic and revenue -- as well as user gains -- as evidence of good returns on mobile investments.

So while it's tempting to think of Yahoo! stock in terms of the potential gains from its 24% stake in Alibaba, strategically Mayer has bigger aims. She wants Yahoo! to be users' go-to for news and other content while on the go. By the numbers, investors have every reason to believe that she can.

Now it's your turn to weigh in. What did you think of Yahoo!'s earnings report? Please watch the video to get the full story and then leave a comment to let us know your take, including whether you would buy, sell, or short Yahoo! stock at current prices.