Plaxo claims it has seen a massive surge of traffic after becoming the first company to release an application based on Google's OpenSocial API.

Google unveiledthe APIs, designed to help developers build social networking applications that can run on multiple sites, at the start of the month.

John McCrea, Plaxo's vice president of marketing, said the company's Pulse social network saw its traffic jump from about 200,000 to 1 million in the first two weeks of availability. From the moment OpenSocial was announced, Pulse "has experienced a surge so strong that we had to expedite a hardware order, and shift focus temporarily from the new features to scalability," McCrea said in a blog post. "In a single day, the rate of wiring up the Pulse social graph jumped by an order-of-magnitude.”

Pulse lets users build social networks based on content produced by their contacts. Using OpenSocial, Pulse users can create professional and personal profiles that include photos, contact information and settings. Any application written in OpenSocial can be embedded in the profiles.

"The idea was that we could play a role in the emergence of a social web that was as open as the web itself," McCrea said. "We let users bring in content from the sites they were already using, and we let them take their data out through a variety of mechanisms, including RSS and a life-streaming widget."

Kristen Nicole, a blogger on social networking site Mashable, noted in a blog post that Plaxo's success says a lot about the potential for OpenSocial.

"But this seems to be a particularly unique situation for Plaxo Pulse, as it operates from the standpoint of highlighting your existing relationships," she noted. "Wrap that up in an application that further works from these relationships, and you have a convenient manner in which users can extensively expand activity going on within their Pulse accounts."