Plaxo today announced that they have just signed an agreement to be acquired by Comcast. Details of the price were not disclosed but it is rumored to be in the $140 - $175 million range.

The company blog says “Plaxo Pulse is to become central to creating a unified “Social Media” experience across the web and television”. Not sure what exactly that means for Comcast? Given that 75% of Plaxo’s users are business users. I am surprised that Plaxo was not acquired by Google or Cisco.

Google because Plaxo could have been the center piece for its OpenSocial and Friends Connect initiatives, it could provide Google with its own LinkedIn type service and become a sourcing pool to extend Google Apps into the enterprise. Further Plaxo is funded by Google’s Founding Board Member Ram Shriram. So the sale would not have been a stretch.

Even more puzzling is why Cisco didn’t jump on it - it would have been great to drive adoption of Cisco’s Webex products. In fact Cisco has invested close to $15 million in Plaxo. At the time of the investment a Cisco spokes person said “The investment by Cisco reflects an interest in the emerging social-networking space, Plaxo’s strength lies in its ability to connect people with those they already know or do business with”.

For Comcast this is an expensive way to get into Social Media when there are far better alternatives that are more synergistic to its core business (maybe Comcast knows something I don’t). Plaxo’s site is still in beta after all these years and millions of dollars in development. Further, their traffic is headed downward. Plaxo management probably decided that any exit is better than no exit. Your thoughts?