I have been thinking about eBay + Skype, and it is beginning to come together for me.  eBay’s presentation on the topic helps by putting it in the context of "The Power of 3", and the way they represent it, it makes sense.  I am skeptical of the 1% overlap figure, though.

Adjacent to the synergies they claim, I especially like how they are viewing their challenge as "removing friction".

Friction: Trust -> Solution: Ratings
Friction: Payments -> Solution: PayPal
Friction: Communications -> Solution: Skype