Core Viewpoint - The shutdown of 91 Mobile Assistant marks the end of a once-prominent application, which will cease all services on September 27, 2025, resulting in permanent data loss for users [1] Group 1: Acquisition and Initial Success - Baidu's acquisition of 91 Mobile Assistant for $1.9 billion in 2013 is now considered one of its most unsuccessful deals, failing to provide the anticipated entry into the mobile internet market [3] - The acquisition was initially seen as a strategic move, similar to Baidu's earlier purchase of hao123 for 50 million RMB, which significantly boosted its user base during the PC internet era [3] - Following the acquisition, 91 Mobile Assistant helped Baidu achieve a leading position in China's mobile application distribution market, with a market share of 41.2% in Q4 2013 [5] Group 2: Decline of 91 Mobile Assistant - The decline of 91 Mobile Assistant began as the mobile internet ecosystem matured, leading to a decrease in its user base, particularly among iOS users due to Apple's improvements that made jailbreaking less necessary [6][8] - Android manufacturers began to suppress third-party application stores like 91 Mobile Assistant, as they shifted focus to their own app stores for profit [10] - Users faced increasing barriers when attempting to install apps from third-party sources, leading to a decline in 91 Mobile Assistant's user base as they opted for official app stores instead [11] Group 3: Failed Revitalization Efforts - Baidu attempted to leverage 91 Mobile Assistant to revitalize its gaming business in 2021, but faced significant regulatory challenges and a halt in game approvals, leading to the failure of this initiative [13]