Unsub is already used by hundreds of libraries and several large consortia, even though it was only launched in November 2019.
One of our earliest users, The State University of New York, has publicly stated that Unsub (previously called Unpaywall Journals) helped them cancel their Big Deal with Elsevier in early 2020, saving millions of dollars: press release, Science article.
CRKN, the consortium of universities in Canada, has publicly announced their subscription.
MIT recently walked away from their Elsevier subscriptions. Shortly afterwards, Director of Libraries Chris Bourg tweeted:
-> The work that @jasonpriem & @researchremix of @unsub_org do is incredibly important -- was super helpful in understanding our alternatives and making sure we had a sound strategy in place if/when we ended up out of contract with any publisher
University of Oklahoma has been an enthusiastic user of Unsub even after walking away from their Big Deals. Karen Rupp-Serrano, Interim Dean | University of Oklahoma Libraries, says:
-> We have found Unsub to be a great tool in our serials review toolbox. It offers the essential data we use in review projects, and in one place for ease of use. It offers important data we were unable to effectively marshall in the past, specifically citation and authorship data, open access data, ‘instant fulfillment’ and forecasting, all for an incredibly reasonable price. The staff are quick to respond to questions or concerns, and actively seek customer feedback to continuously improve their product.
We also have a publicly-viewable user group where some users discuss their experiences: https://groups.google.com/forum/#!forum/unsub-discuss
There is a press page that includes articles about Unsub: https://unsub.org/press
And a few other articles and conference presentations that mention Unsub.