I don't know how unusual I am / was, but I would sometimes download the Libronix files of books I wasn't going to buy immediately, but which I might purchase subsequently. Then I could do searches on all known resources, and find out how many times the word I was searching on appeared in locked resources. Sometimes this prompted me to purchase the said resource, just so I could satisfy my curiousity as to how the word in question was being used. More importantly, it gave me a way of interrogating the resource to see if it would really provide the kind of help I hoped it would.
Now ... I really really miss this from Logos 4.
In fact, it is all part of they way that Logos 4 keeps me at arms distance from my resources. I don't like the new model, and I really wish it would move back more in the direction of Logos 3.