The rhetoric related to benefits of Open Government Data (OGD) seems to lack anchor in practice affecting practitioners and empirical evidence restraining academia. This rhetoric could be hard to see for those already persuaded. As such, the rhetoric could contain inconsistencies that are based more on myths than facts, contributing to the slow pace of OGD development. OGD is sometimes based on dogmatic rhetoric that is overly simplistic, which hides significant benefits and blocks potential audiences from seeing the practical applications of OGD. The purpose of the present study was to analyse the persuasiveness of present OGD arguments from a rhetorical perspective to identify rhetorical patterns. We conducted desktop research, investigating the rhetoric of eight websites emphasising OGD benefits. Our findings include four common patterns of the rhetoric involving persuasion and dissuasion. The rhetoric contains paradoxes of promises and discoveries, which we categorised as the grand quest, promised opportunities, tribal solidarity, and the silver bullet patterns. A further finding was two mythical paradoxes: (1) promises versus discovery and (2) proving while arguing.