眾所周知，矽谷聚集全球人才、技術、資金，形成全球最繁榮的科技產業群聚。但近年來，新創企業卻不再以矽谷為首選，反而朝向北邊的舊金山市聚集。這現象似乎與產業群聚理論中認為空間能不斷正向強化的解釋相悖。因此，本文嘗試從統計數據、文獻、創業實務，並就理論探討其成因。本文認為，其可能除了金融風暴造成地租誘因；都會區完善的資通訊基礎；創業環境支持發展之外，平台經濟模式特別適合在都會區發展，成為新創平台企業快速創造流量、擴充展銷規模的絕佳環境。 就理論解釋上，都會區因為空間鄰近性，多元異質性的交流帶來更多知識外溢、人際網絡的優勢持續佔有重要性，然而，不同的是，平台型的新創企業因為技術相近，彼此呈現獨立激烈競爭，必需透過不斷調整服務特色，快速軸轉商業模式來爭取優勢。而消費者在接受創新產品過程中，廠商間必須亦步亦趨地在都會聚集，共同開發共享市場，非默契地形成合作共識，與傳統理論中，強調地方網絡支持協力的制度模式截然不同。在都會空間意涵上，平台型新創企業的崛起，除了改變了生產與消費制度，也帶來調適修補都市負外部性的潛力，但同時卻也可能帶來社會隱憂風險，因此，如何平衡公共價值與創新驅力的治理亦是重要挑戰。

Early since the 80s, Silicon Valley has become the world-class tech-pole attracted talent, capitals, and enterprises as a giant cluster in a self-enforcement way to the economic prosperity. However, in recent years, there are evidences showed that startups migrated from Silicon Valley to the north: San Francisco city. The emerging phenomenon is unable to explain by the traditional cluster theories by the following question: “Why San Francisco is a better place than Silicon Valley which is still in the crown of technology-industries region in the world? The explanations are exogenous by the rent sharply decreased after the 2007 financial crisis, comprehensive urban ICT infrastructure, and the supportive entrepreneurship ecosystem. The major endogenous reasoning is because of the business model of the platform enterprises has advantages to grow, exhibition, create online flow and scaling up in the urban environment. From the perspective of the cluster theory, the spatial proximity and the diversity in the urban environment bring more positive effect of knowledge spillover and the networking as usual arguments. The difference is that platform enterprises are independently competing each other because of the similarity on technology and targeting, as the urban consumers are gradually educated by the innovative product and service, these startups agglomerate closely and keep catching up as a pivot to adapt rapidly for the market. In implication of the urban environment, the emergence of these platform-startup enterprises are not only facilitating the institutional change in the relations between production and consumption, but having the potential to patch the negative urban externalities. However, as it may bring the risk to society as well, the critical challenge would be how to balance with the innovation both for public and private sectors.