Palo Alto, Calif. -- Pinterest, the pinboard-style social photo sharing site operated by Palo Alto-based Cold Brew Labs, has landed a new $100 million round of funding at a $1.5 billion valuation, led by Japanese online marketplace Rakuten, the companies said on Thursday. Previous backers Andreessen Horowitz, Bessemer Venture Partners and FirstMark Capital, as well as a number of angel investors, also participated. Pinterest said it will use the funds to improve its service and expand its community globally. The investment also marks the launch of a partnership with Rakuten, aimed at helping Pinterest expand in Japan and Rakuten's 17 other markets. "We see tremendous synergies between Pinterest's vision and Rakuten's model for e-commerce," said Rakuten CEO Hiroshi Mikitani. "Rakuten looks forward to introducing Pinterest to the Japanese market as well as other markets around the world."