Yahoo_logonewUPDATE, 3:15 PM: Yahoo CEO Marissa Mayer was bullish on the sales gains and talked up the company’s results in four key investment businesses: mobile, video, native and social, with 98% ad growth year over year. (Mayer said mobile was the most important of those pillars, by the way.) Alibaba, meanwhile, remained a hot topic after the Chinese e-commerce company reported 66% sales growth — a major catalyst on the sales side but still a bit of a mystery to U.S. investors who will get more of a peek under the hood once it starts trading on the NYSE. An institutional investor asked what Yahoo expects to do with the potential $12B windfall from an Alibaba IPO, and Mayer answered that the company would remain a “good steward of our capital.” No word on further original content deals, other than Mayer saying expect more of the same mix of deals between tuck-in and outright acquisitions.

PREVIOUS, 1:55 PM: Yahoo shares bumped up in after-hours trading after the Web giant reported its first sales gains in more than a year. The news comes as the company reported revenue of $1.09B during the quarter, better than the $1.08B analysts expected and up from $1.07B a year ago. Net income was $311.6M, down from $390.3M year-over-year. Profit came in at 38 cents a share, a penny better than estimates. The big reason for optimism though were the sales gains: the company said it logged its first quarter of year-over-year growth since 2010. The stock is down 15% for the year. The company will have an analyst call this afternoon, during which it certainly will be asked how much of the good news come from Yahoo’s 24% stake in Alibaba, which is being eyed for an IPO. Yahoo will also be asked about its video initiatives, coming off reports of a rumored acquisition of News Distribution Network. DEVELOPING

Four investment business see growth: mobile, video, native and social up 98% year over year