After graduating from law school, Rosenblatt took a job at Brobeck, Phleger & Harrison, in Los Angeles, but quit after six months, citing boredom.

[8][9] Rosenblatt replaced one of the founders, Craig Pickering, as CEO in July 1996 and took on the additional role of chairman of the board in January 1997.

[9] In April 1999, Verio, Inc. teamed up with iMALL and First Data to create VerioStore, a product selling e-commerce services.

[7] His participation was part of a larger effort by investors to reconfigure the business into a hybrid online and offline venture that was structured to be less dependent on the erratic flow of advertising dollars.

[8][16] Rosenblatt became CEO of Superdudes.net, an online gaming community where users created their own Superhero character and participated in global social networking in 2002.

[2][17] In February 2004, Rosenblatt became CEO of Intermix Media (formerly eUniverse, Inc.), where he led the growth of Myspace.com from an unknown website into a popular Internet property.

Intermix acknowledged Spitzer's allegation, but stated that it was part of an outdated practice put in place by previous leadership, and the company no longer installed software without first notifying the customer.

The founder and former CEO of Intermix Media Inc., Brad Greenspan, was fined US$750,000 as part of an agreement with Spitzer to end the investigation against him.

[22][23] The case was dismissed on Friday, October 6, 2006, when Judge Carolyn Kuhl determined that shareholders of Intermix Media, Inc. had been lawfully informed prior to voting on the transaction.

[28][29] In January 2008, Demand Media partnered with Lance Armstrong and the (LAF) to build the daily health, lifestyle and fitness website, Livestrong.com.

[39] He was recognized as one of The 50 Smartest People in Tech by Fortune magazine and one of the Most Admired CEOs by Los Angeles Business Journal.