The DNA aka corporate culture, IMO, cannot be bought or acquired, it has to be built ground up. Some companies excel in online search (who am I kidding, ONE company dominates search), some excel in selling
to corporates, some excel in selling services and, startups, hope to excel in changing the paradigm. Problems tend to 'happen' when companies think they can do something else also. I am not saying it is impossible to change the culture, just really, really, really hard, and requires a lot of patience, time, money and precise management focus to pull it off.
The DNA of an organization is determined by the founding team in startups, the management team and long time employees in more established companies. This DNA is strengthened by the hiring tendencies in these companies. Hiring managers tend to hire people who fit well into the existing corporate culture. A startup has a culture of doing more with less in the least possible time. Product development in established companies follow (hopefully) sound software engineering principles with release dates being in years and have the luxury of time and money to take the long term view. IT service companies follow processes, CMM, ISO, SDLC, what have you, a premium is placed on process, people here tend to be replaceable resources.
So once you start rolling the ball, the DNA tends to be positively reinforced by the people and their hiring preferences.
Positive Reinforcement of DNA:
Why has Microsoft not been successful in the online search business? It most definitely is not because of a lack of raw brain power. For every smart guy in Google there is an equally smart guy in Microsoft and the same holds true for every smart gal. Its not because of money. Microsoft has tons of it. I am sure Bill and Steve really want to dominate search and so there goes management priorities. The only thing left is the DNA. Microsoft has been widely successful when they control the OS, when they control the means to develop for the OS resulting in a general "not invented here" mentality. They have no doubt hired the best brains but these best brains either by nature or nurture deliver the best products only when they control everything. In Search nothing is under your control, you just hope people will use your search habitually.
Yahoo & Microsoft Cultural Chasm
Yahoo board (at least for the time being) has rejected Microsoft's offer. I have serious questions regarding their DNA compatibility if the deal ever happens. Yahoo has been a web company since its inception. They need to deliver products in web speed as they compete with the 800 pound gorilla called Google and a score of nifty startups constantly sniping at their heels. Yahoo has been aggressively going open source with their UI library, acquired Zimbra, etc. Microsoft on the other hand is kind of similar to IBM of the late 80's, still dominant but worried that a computing paradigm shift will pull the rug from under their feet. Microsoft is programmed to operate and deliver products on multi-year release schedules. This culture difference is just not restricted to development teams but extends also to sales, marketing and support functions. Bringing the two organization under a single command and control is a chasm that may be too wide to cross even for Microsoft. Roger Ehrenberg has an interesting article regarding these cultural differences.
Roger uses a very interesting metaphor, he likens Yahoo to a football locker room and Microsoft to a baseball locker room. I could'nt resist extending the metaphor to startups, like us - OdinJObs.com, who wants to change dramatically how things our done. I would liken Odinjobs.com to Base jumpers earning their base numbers.