text: Either by ensuring the continuing availability of information, or by deliberately caching content that might get deleted or removed, Web archiving services play an increasingly important role in today's information ecosystem. Among these, the Wayback Machine has been proactively archiving, since 2001, versions of a large number of Web pages, while newer services like archive.is allow users to create on-demand snapshots of specific Web pages, which serve as time capsules that can be shared across the Web. In this paper, we present a large-scale analysis of Web archiving services and their use on social media, aiming to shed light on the actors involved in this ecosystem, the content that gets archived, and how it is shared. To this end, we crawl and study: 1) 21M URLs, spanning almost two years, from archive.is; and 2) 356K archive.is plus 391K Wayback Machine URLs that were shared on four social networks: Reddit, Twitter, Gab, and 4chan's Politically Incorrect board ( pol ) over 14 months. We observe that news and social media posts are the most common types of content archived, likely due to their perceived ephemeral and or controversial nature. Moreover, URLs of archiving services are extensively shared on "fringe" communities within Reddit and 4chan to preserve possibly contentious content. Lastly, we find evidence of moderators nudging or even forcing users to use archives, instead of direct links, for news sources with opposing ideologies, potentially depriving them of ad revenue.
  @cite_28: 
  @cite_15: 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.
  @cite_4: With its seemingly limitless scope, the World Wide Web promises enormous advantages, along with enormous problems, to researchers who seek to use it as a source of data. Websites change continually and a high level of flux makes it challenging to capture a snapshot of the web, or even a cross-section of a small subset of the web. A web archive, such as those at the Internet Archive, promises to store and deliver repeated cross-sections of the entire web, and it also offers the potential for longitudinal analysis. Whether this potential is realized depends on the extent to which the archive has truly captured the web. Therefore, a crucial question for Internet researchers is: ‘How good are the archival data?’ We ask if there are systematic biases in the Internet Archive, using a case study to address this question. Specifically, we are interested in whether biases exist in the British websites stored in the Internet Archive data. We find that the Internet Archive contains a surprisingly small subset, about 24 , of the webpages of the website that we use for our case study (the travel site, TripAdvisor). Furthermore, the subset of data we found in the Internet Archive appears to be biased and is not a random sample of the webpages on the site. The archived data we examine has a bias toward prominent webpages. This bias could create serious problems for research using archived websites.
  @cite_3: The Memento Project's archive access additions to HTTP have enabled development of new web archive access user interfaces. After experiencing this web time travel, the in- evitable question that comes to mind is "How much of the Web is archived?" This question is studied by approximating the Web via sampling URIs from DMOZ, Delicious, Bitly, and search engine indexes and measuring number of archive copies available in various public web archives. The results indicate that 35 -90 of URIs have at least one archived copy, 17 -49 have two to five copies, 1 -8 have six to ten copies, and 8 -63 at least ten copies. The number of URI copies varies as a function of time, but only 14.6-31.3 of URIs are archived more than once per month.
summary: @cite_15 analyze 6M access logs from the Wayback Machine, aiming to understand what users are looking for, and why they use it. They find that users visit the site predominantly via referrals, and that they mostly look for English pages, while most popular country-specific domains are from Japan, Russia, and Germany. @cite_28 simulate a Web archiving service, studying social discourse through the URLs as well as relevant entities and metadata, by analyzing millions of tweets as well as a case study related to fake news. @cite_3 measure how much content is available on Web archiving services: they sample URL shorteners and search engines, query 12 public archives, and find that 35 , @cite_4 assess whether the Wayback Machine archives a purely random sample of Web pages, finding some bias towards more visible and prominent pages.