In its July 2010 MessageLabs Intelligence Report, Symantec reported that the percentage of spam containing shortened hyperlinks has increased significantly over the last year.
The report said that spam containing shortened hyperlinks hit a one day peak of 18 percent, or 23.4 billion spam emails, on April 30, 2010 doubling last year’s peak levels when spam with shortened hyperlinks accounted for 9.3 percent of spam, more than 10 billion spam emails on July 28, 2009.
MessageLabs Intelligence found that on average one website visit is generated for every 74,000 spam emails containing a shortened URL link. The most frequently visited shortened links from spam received more than 63,000 website visits.
Source: Symantec / MessageLabs