A look back at Microsoft's advertising-related acquisitions

On March 14, Microsoft acquired another Web-advertising vendor, Rapt.

It's clear: The Redmondians are building out their advertising portfolio through acquisitions.

Microsoft was thwarted in its attempt to buy (and then block-Google's acquisition of) DoubleClick. And it's still uncertain whether Microsoft will pull off its acquisition of Yahoo, which would be the grand-daddy of not just all advertising-specific acquisitions, but all Microsoft acquisitions in general. (Yes, Microsoft and Yahoo allegedly are talking, sans lawyers. The actual Microsoft acquisition of Yahoo could still face a long and rocky road ahead.)

In the interim, Microsoft has managed to buy a number of other niche advertising-related players over the past couple of years, including:

2008: Rapt -- advertising yield-management technology for digital publishers 2008: YaData -- online advertising targeting technology 2007: Multimap -- location-based services 2007: aQuantive -- advertising platform,tools and services 2007: adECN -- advertising-exchange platform 2007: ScreenTonic -- mobile ad-serving platform 2007: TellMe -- voice and mobile-search services 2006: Massive -- in-game advertising platform

Microsoft CEO Steve Ballmer was quoted late last year as saying he expected Microsoft to buy about 20 companies a year for the next five years, with most being in the $50 million to $1 billion range. I wonder if Microsoft's $44 billion bid for Yahoo will end up reducing that total.