Upheaval at AOL following its spin off from Time Warner last December has not hurt its dominance of the internet ad network market.

AOL Advertising was the top internet ad network in the US in December 2009, followed by the Yahoo Network and the Google Ad Network, according to a ranking of the top 15 ad networks based on their reach among US internet users, by comScore, Inc.

Last month the AOL network reached 187 million US internet users - or 91% of the total audience - and grew 8% over the same period in 2008, comScore reported. (via MarketingCharts).

The #2 ranked Yahoo Network reached 180.9 million users (also up 8% over December 2008), and the #3 ranked Google Ad Network reaches 178.1 million (up 9%).

Big Plans

AOL did a lot of planning leading up to its reinvention in December. CEO Tim Armstrong's go-to-market strategy for the brand is to become the top creator of digital content on the web, writes MediaBuyerPlanner.

According to Armstrong, content is the one area on the web that hasn’t seen its full potential; his plans call for a significant increase in the amount of content AOL produces.

Marketing is also to be tied into this strategy - AOL will allow advertisers to work with its content creation team to create custom products.

AOL is also choosing to keep its ad sales staff relatively intact even as it continued to trim its workforce, according to Business Insider.