Usage Statistics

Below are the general usage statistics of our catalog. We are continuously working with and Metabase to provide better visualizations.

For sales, we gather data from Lightning Source (online sales of the Uitgeverij imprint), Paypal (used in the past for invoicing of direct sales), InvoiceNinja (our current invoicing system for direct sales), and KDP (for online sales). These data can be readily compared as each data point refers to the sale of one print book.

For downloads, we collect data from free and paid download website plugins we used in the past before depositing our books in OAPEN, JSTOR, Project MUSE, Google Books, and the Internet Archive. The comparison of data points is little more clouded here. The data from OAPEN, Project MUSE, Google Books, and the Internet Archive show an interaction with the ebook, be that a full download to a local drive or consulting a page on the online interface. JSTOR furthermore splits our ebooks into component chapters, access to which is counted separately.

The data sets behind all the graphs and tables below are downloadable under a CC0 license by clicking the cloud icon in the lower right corner.

Whenever a data source is marked “(Legacy)” this means it is no longer actively updated. As platforms update or change their reporting formats, we sometimes need to create new tables to accommodate these.

Totals per Month

The following graphs provide sales and download data collated per month.

Totals per Book

The following tables provide sales and download data collated per book. Internet Archive data per book are currently not yet available.

Totals per Country

We receive country-specific data from the following platforms: JSTOR, Project MUSE, and the Internet Archive.

CrossRef Events

CrossRef event data show DOI reference events such as a citation in a dataset or patent, a mention in a news article, Wikipedia page, or on a blog, or discussion and comment on social media. Monitored are sources such as Wikipedia, WordPress, and Reddit.