Santa Monica-based Adconion Media Group, an online advertising network, announced today that it has acquired certain assets of Joost, the online video site founded by Skype founders Janus Friis and Niklas Zennstrom. Financial terms of the buy were not disclosed. Adconion Media said it would continue to operate Joost.com, and use it to bring additional "scale" and content to its network. Adconion offers pre-roll ad placement for its clients. Janus Friis of Joost said in a statement that the firm had been actively exploring "strategic options" for the firm, and decided the sale of its assets was in the best interests of the firm.