All of the books I’ve received through this program have been paid for by the local library and other city funds.
I can also walk into the library and there will be a shelf of free childrens books. Not used, brand new. Stacks of them to take home and keep.
The engine already existed, our public library system.
> The engine already existed, our public library system
How good one's library is depends on how well-off the operating local government is. The Imagination Library is more egalitarian because it's often funded at county and state-level, so kids with underfunded libraries get the same level of access as other kids from wealthier zip codes
The intention of this program was to get books in the hands of children, who might not have access to a public library. The books were kept free in order to combat the shame often associated with not being able to afford books for your kids. These two services might be catering to two separate (though sometimes overlapping) audiences.