For the second time in a month, a high-ranking employee with the social blogging website Tumblr has announced their departure as the company begins looking for ways to generate revenue.

Matt Hackett, who was named head of brand strategy and marketing at the website in September, announced via email on Friday that he has decided to leave the company. Hackett was originally hired as vice president of engineering in February 2010 before accepting his role as head of marketing nine months ago.

In the email, Hackett said that he consulted with several people including Tumblr founder David Karp before reaching the decision to leave the company.

The departure comes almost two weeks after Tumblr’s president John Maloney announced he was resigning from his position. Maloney, who joined the company in 2008, said he would continue to stay close to Karp and others at Tumblr. “There’s more work to do and I want to help see it (through),” Maloney wrote on his blog.

Maloney’s resignation and Hackett’s departure comes shortly after Karp unveiled Tumblr’s advertisement model, which Karp hopes will start generating money for the blogging platform. The advertisements currently appear in the “Radar” section of a Tumblr user’s dashboard, which get 120 million impressions daily according to Karp.

It’s unclear if Hackett’s departure is linked to the new advertising model. Hackett said by email his last day was Friday.

In the message sent on Friday, Hackett gave an email address for people to keep in touch with him and linked to his blog, which is hosted on Tumblr.