Perception and reality sometimes have a twisted relationship. That’s particularly true in cases where being perceived as the leader makes you the leader. We tend to see these types of self-fulfilling prophecies in aggregator / market maker and other critical mass businesses. Markets that have these characteristics tend to exhibit spending and bidding wars to reach/maintain dominance.
Using Occam’s Razor as a guide, this naïve explanation may just be why it made sense for Google to outbid Microsoft for DoubleClick. I discount the economics that DoubleClick can bring to Google for two reasons: (a) some of DoubleClick’s current customers/partners will look for alternatives and (b) Google is still learning how to handle large acquisitions. Also, from an economic standpoint, Google would not have been threatened in the short or medium run by DoubleClick going to Yahoo! or Microsoft. However, the opportunity cost of losing DoubleClick from a perception standpoint was huge. It would have exposed a crack in the armor.