When I heard about the 3 month free trial at Scribd, and looked at their collection (they have a number of niche publishers that the public library is never going to stock in bulk), I only had to make sure I had
the correct kind of device to use it properly before signing up.
That's telling in and
of itself — a user agent basically tells websites what
kind of browser,
device, and operating system is connecting to it, so that the website serves the
correct version
of the web page.