The microhistory of the Amsterdam-based Sebastiaan Petzold († 1704) demonstrates that in the Early Modern Period booksellers without a network were hardly able to manage professionally in the Republic of Letters. Petzold relied especially on patronage from Socinianist circles. The Socinian theologian Samuel Crellius (1660-1747) saw to it that Petzold was able to publish three highly controversial Socinian works, including the notorious Platonisme devoilé (1700). Petzold was also introduced to some prominent English booksellers thanks to Crell, which provided him with access to the international market. Another patron was the Berlin court preacher Daniel Ernst Jablonski (1660-1741), who recommended Petzold to Gottfried Wilhelm Leibniz. In Amsterdam the literary society ‘In Magnis Voluisse Sat Est’ commissioned Petzold to publish the complete works of Lucretius, an Epicurean work which was a favourite in anti-clerical circles. In spite of this support, in the end Petzold was besieged by creditors, instead of authors thronging at his door.