document: we . b : the web of short urls Short URLs have become ubiquitous . Especially popular within social networking services , short URLs have seen a significant increase in their usage over the past years , mostly due to Twitter 's restriction of message length to 140 characters . In this paper , we provide a first characterization on the usage of short URLs . Specifically , our goal is to examine the content short URLs point to , how they are published , their popularity and activity over time , as well as their potential impact on the performance of the web . Our study is based on traces of short URLs as seen from two different perspectives : i ) collected through a large-scale crawl of URL shortening services , and ii ) collected by crawling Twitter messages . The former provides a general characterization on the usage of short URLs , while the latter provides a more focused view on how certain communities use shortening services . Our analysis highlights that domain and website popularity , as seen from short URLs , significantly differs from the distributions provided by well publicised services such as Alexa . The set of most popular websites pointed to by short URLs appears stable over time , despite the fact that short URLs have a limited high popularity lifetime . Surprisingly short URLs are not ephemeral , as a significant fraction , roughly 50 % , appears active for more than three months . Overall , our study emphasizes the fact that short URLs reflect an `` alternative '' web and , hence , provide an additional view on web usage and content consumption complementing traditional measurement sources . Furthermore , our study reveals the need for alternative shortening architectures that will eliminate the non-negligible performance penalty imposed by today 's shortening services .
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