Digital news publishers strive to balance revenue streams in their business models: as standard advertising declines, alternatives for sustaining digital journalism arise in the forms of sponsored content, user donations and payments¿one-off purchases, subscriptions or memberships, public or private grants, electronic commerce, events and consulting. An exhaustive study found 2874 active online news publications in Spain, and it observed the adoption of such models in early 2021. Advertising remains the most popular source of income for digital news operations (85.8%) and most sites rely on just one or two revenue streams (74.5%). We compare the cases in our census by their origin (digital-native or non-native), geography (local/regional or national/global) and topic scope (generalist or specialized). We find that traditional, national and specialized online media have a broader and more innovative revenue mix than digital-native, regional or local and general-interest news outlets. The comprehensiveness of this pioneering study sheds light for the first time on the risk that the lack of diversification and innovation in funding sources may imperil the financial sustainability of some online news operations in Spain, mostly those with a smaller scope and no backing from a traditional business, according to the results we present here.