With this in mind, Web site uptime firm Pingdom tested them against each other. For speed, the fastest to the slowest were ls.gd, Bit.ly, Ow.ly, Su.pr, TinyURL, Twurl, Tr.im, Cli.gs and the slowest—by a decent margin—was Snipurl. But the report also looked at reliability: "Perhaps even more important than how fast these services are (many would argue a few hundred milliseconds in load time won’t make a huge difference) is how reliable they are. Once a short URL has been created, how much can you trust that it will work and keep redirecting to your target site?" The reliable ranking, from most to least, was Ow.ly (the only tested service that suffered zero downtime), Bit.ly, Su.pr, TinyURL, ls.gd, Snipurl, Cli.gs, Twurl and Tr.im.
With social networking becoming a critical tool in the E-Commerce director arsenal—whether that's Facebook, MySpace, YouTube or Twitter—the power of a tiny piece of programming called a URL shortener is something that retailers would rather not leave to chance. Given how easily the tools can be used to secretly ship a customer to an unintended Web address, security is a factor, too.