Baidu (BIDU) is acquiring top Chinese mobile app distributor 91 Wireless from Hong Kong-listed NetDragon and minority shareholders for $1.9B. 91 was estimated to host ~900K Android apps from ~93K developers (#1 in China) at the end of 2012; the company has also developed several popular apps. Baidu is paying steep multiples for rapid growth: NetDragon's mobile ops posted 2012 revenue of $46M, and Q1 revenue of $23.6M (+42% Q/Q and +219% Y/Y). The deal follows Baidu's purchases of video sites PPS and iQiyi, and is another step towards building a Google-like mobile ecosystem ... and perhaps also lowering its search dependence in the face of growing competition and mobile monetization issues. 91 competes with Qihoo's (QIHU) Mobile Assistant app store.