Audiobooks - OneClickdigital
Brilliance, Audible - these are owned by Amazon and do not sell to libraries.

Pottermore - allowed to purchase HP series as of April 2016.  Copies expire after 5 years.  This is the only audiobook company with an expiration.

eBooks - 3M Cloud Library
HarperCollins: 26 checkout limit per copy; no time expiration on copies

Penguin Random House: Inflated price (up to $65 for new release);no checkout limit or expiration of copies

Scholastic: Copies expire 2 years after purchase (regardless of checkouts)

Disney: 26 checkout limit per copy; no time expiration.

Simon & Schuster: Copies expire 1 year after purchase (regardless of number of checkouts); libraries required to enroll in "buy it now" options on platform.

Macmillan: copies expire after 52 checkouts or 2 years, whichever comes first, plus high price per copy (usually $60-$40).

Not Available to Purchase

• Hachette (not available to consortia)