Never underestimate the power of two-way sync and large social networks. A week ago, MySpace turned on two-way sync with Twitter, allowing members to post their status updates to Twitter directly from MySpace. Those updates appear in Twitter with a short link back to MySpace, using MySpace’s own link shortener, “http://lnk.ms/.”

MySpace status updates are now flooding Twitter. Those MySpace short links account for 17 percent of all passed links on Twitter, according to Tweetmeme, making it the No. 2 link shortener after bit.ly, which rules with 68 percent. The day of the launch, lnk.ms accounted for 8.56 percent of all passed links on Twitter. MySpace has had its own short URL for about six months, but it’s only now taking off with two-way sync.

The MySpace short links can be used for any URL, but it is the status updates which seem to be what they are being used for the most. So that’s not really a huge threat to bit.ly, even if it does represent a large and growing volume of short links on Twitter. Not everyone can see those status updates once they click through. You typically have to be that person’s friend on MySpace to even see the update. But the proliferation of lnk.ms links does show how easy it is for a large service like MySpace to inject itself into the conversation on Twitter with a simple feature like two-way sync.