After spending much of the past year at a mediocre three-star rank, SINA (Nasdaq: SINA) has impressed enough top-performing members of our 165,000-strong Motley Fool CAPS community to climb all the way to four stars. A total of 771 members have given their opinion on the Chinese online media company, with many of them offering analysis and commentary explaining the recent optimism.

SINA has been reaping the benefits of a strengthening online ad market in China, and CAPS members like where it's headed. The company holds a lead over competitors (Nasdaq: SOHU) and Tencent Holdings, with 34% of China's portal advertising market. Investors also liked the numbers in its recent earnings results: While value-priced Sohu's ad revenue was 4% higher in the first quarter, SINA was well above that level, with a 26% jump in ad revenue that helped it offset weakness in its mobile business.

Gains from SINA's stake in E-House (NYSE: EJ) subsidiary China Real Estate Information, which reported much higher first-quarter revenue, helped contribute to SINA's huge leap in its recent quarterly earnings, and profits still blew past analysts' expectations on an adjusted basis. While VisionChina Media (Nasdaq: VISN) recently reported lower ad revenue in its out-of-home ad networks, accelerating online ad revenue reported by other Chinese online companies such as search engine Baidu (Nasdaq: BIDU) has boosted many investors'  confidence in overall online advertising.

Investors recognize that SINA has its challenges: The company is factoring out any further revenue from its long-term cooperation with Google (Nasdaq: GOOG) after Google aimed to avoid China's censorship rules. And while mobile-services revenue has been hurt by the Chinese government's crackdown on mobile content, SINA expects revenue to stabilize in the third quarter if there are no further changes. There also could be growth by acquisition: Despite the unsuccessful attempt to pick up assets from Focus Media (Nasdaq: FMCN) last year, SINA is still looking for opportunities.

Do you think SINA deserves its improved status? Add your thoughts in the comments box below on this page, or head over to CAPS to rate the company and check out all the information and opinions the community offers, absolutely free.

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Fool contributor Dave Mock recently upgraded his Pictionary aptitude from dismal to passable. He doesn't own shares of companies mentioned here. Baidu, Google, and are Rule Breakers recommendations. SINA is a Stock Advisor selection. The Fool's disclosure policy can do the moonwalk, robot, and cabbage patch better than you.