Google is leading the field in advertising thanks to their early purchase of Applied Semantics and the subsequent integration of it into their search solutions. Their next acquisition of DoubleClick defiantly helps their market share in online advertising since DoubleClick was probably the biggest online advertising company around.

Yahoo and Microsoft aren’t far behind Google, Yahoo bought 20% of Right Media for $680M, and a 35%-50% stake in Tyroo Media for an undisclosed sum of cash, Microsoft bought aQuantive and ScreenTonic to help their online advertising market share and now AOL continues their buy-out for market share game.

AOL has just bought out Tacoda, a web firm with technology to target advertisers. This is one of many advertising company buy outs by AOL including big boy Advertising.com back in ‘04. They also bought out ADTECH, an adserving company out of Germany and an internet marketing provider based in Sweeden – TradeDoubler and Third Screen Media all in the last 12 months.

It would seem that AOL is still committed to entering this online advertising war with the other 3 big players. Now might be a good time to start an online advertising company, get some investors, acquire lots of clients, use some fancy buzz words and try and get yourself bought out, at the rate these guys are buying up advertising companies there’s not going to be many other big independent advertising companies around in a year or so.