  The Internet Archive's (IA) Wayback Machine is the largest and oldest public
web archive and has become a significant repository of our recent history and
cultural heritage. Despite its importance, there has been little research about
how it is discovered and used. Based on web access logs, we analyze what users
are looking for, why they come to IA, where they come from, and how pages link
to IA. We find that users request English pages the most, followed by the
European languages. Most human users come to web archives because they do not
find the requested pages on the live web. About 65% of the requested archived
pages no longer exist on the live web. We find that more than 82% of human
sessions connect to the Wayback Machine via referrals from other web sites,
while only 15% of robots have referrers. Most of the links (86%) from websites
are to individual archived pages at specific points in time, and of those 83%
no longer exist on the live web.
