I was interested in knowing how much commission does libby take for the service it offers? The article doesn't give the details on "big business" that I was l

I was interested in knowing how much commission does libby take for the service it offers? The article doesn't give the details on "big business" that I was looking for. The only related information was - "The details of the sale were not made public, but Rakuten reported a profit of “about $365.6 million.”" But Rakuten is a big company with multiple products. And 365 Million is "Not Big Profit" - for the service lending Millions of ebooks to millions of customers for over a year. I was curious to know, how much libraries pay per ebook. This might have been set prior to libby /overdrive becoming popular. How much commission does libby take for the service it offers? I am also assuming that most of the US libraries are funded by state tax dollars, through which they buy books, pay their staff and now pay libby.