Ad platform company PubMatic has raised $7.5 million in Series C funding. The company launched 3 years ago and has raised a total of $18 million. The last round of funding was led by Helion Venture Partners. Other investors in this round include DFJ and Nexus Venture Partners. [paidContent]

Nicholas Carlson of BusinessInsider pointed out that there is an awkward video of MySpace PR boss Dani Dudeck. There isn’t a lot of talking, but there is a lot of smiling. Dudeck did not want to be interviewed, but Arrington pulled out a flip camera. This video actually reminds me of Arrington being told off by Laporte featuring keyboard cat. [BI]

Opera Mini was at the top of the Apple App Store and featured across 22 countries when it launched. As a result the Opera Mini browser application was downloaded one million times on the first day. Below is the full press release.

Cramster.com is a website where high school and college students have announced that they have raised $6 million in Series B, led by Primera Capital. Primera Capital Managing Partner Ori Sasson joined the board of directors at Cramster.com as a result.

Apartment social search engine RentWiki.com has raised multimillions in funding from Antares Capital. RentWiki is based in Atlanta, Georgia.

The social network platform company founded by Marc Andreessen and Gina Bianchini has announced some major changes. The first change is that they are stopping free social networks from being created. Existing free networks will be forced to pay going forward.

Ning has raised a total of $120 million and received a valuation of $750 million as of last summer.

The second major change is that the company is reducing their staff by 40%. Below is the full email sent from Ning CEO Jason Rosenthal.

Demand Media is working with Goldman Sachs Group, Inc. (NYSE:GS) to explore a potential IPO. Demand Media has raised a total of $355 million from Goldman Sachs, Spectrum Equity Investors, Generation Partners, and Oak Investment Partners. Demand was founded by former MySpace Chairman Richard Rosenblatt.

Xobni, the company that built a social media platform around Microsoft Outlook has raised $16.2 million in funding according to a filing with the SEC. Khosla Ventures and RRE Ventures led the round of funding in the company. Xobni shows your Facebook, LinkedIn, and Hoover’s contacts within Outlook and can reveal past attachments from contacts. Xobni recently launched an email app for the BlackBerry too. Xobni previously raised $15 million from Y-Combinator, Khosla Ventures, Cisco, First Round Capital, Baseline Ventures, BlackBerry Partners Fund, and Atomico Investments. Will Posterous of RRE Ventures has joined as a new board of director as Xobni. [VentureBeat]