When Ebay first bought Skype, a friend who is knowledgeablee about this business area said, 'I have three theories of why they did that.". 

The problem here is that acquisitions should not be so mysterious that you have three theories on it, the way you have multiple theories on why a date didn't call you back within a week.  Acquisitions are supposed to be done through careful valuation of the company that is being acquired. 

In the case of eBay, my 'theory' is that Niklas Zennstrom convinced eBay that he, Zennstrom, as an official producer of disruptive technology, was ready to disrupt all over eBay's business model.  I'm sure he did this with much hand waving, talk of Google, and some snazzy Powerpoint.  He also probably pointed out that Rupert Murdoch wanted to buy Skype but he wouldn't sell out to the 'man' i.e. someone who owned a traditional media conglomerate.  And besides the 'man', Murdoch, didn't really understand the full extent of the disruptiveness of this technology and would not give Zennstrom and Friis what they were asking for it.

At that point, this is likely what went down:

A senior eBay executive said, "This is crazy we can't buy a company for what he's asking when this service (VoIP) will trend to free in a few years.  Besides, if we need a VoIP service, let's just build our own by buying the components.  Its not exactly secret, how to do this." 

At which point everyone young in the room thought, uh oh old guy doesn't get it alert.  we majorly have to buy this company.  This would have been accompanied by Zennstrom rolling his eyes like he has heard this all before when people have said I don't think your technology, which is free, is so disruptive.

Then they left their boardroom, meet up at a bar (without the doesn't-get-it executive), ordered martinis.  Someone said, 'Hey, have you seen Google Earth.  That is so cool.'  Then Meg Whitman (who hadn't seen Google Earth) thought to herself my God, they have a product with the word 'earth' in it, that's our market!, and turned to Zennstrom "Listen I think I can get them to agree to $4 billion but you're going to have to give me your Powerpoint slides to use."

And so it was.  And now Meg Whitman had to use the word 'ecosystem' when talking to analysts.  I really applaud the communications people, they really digged deep for that one.  I mean anyone can quote a strategy concept from Michael Porter of Harvard Business School (Five Forces - duh) but you really have to know what you're doing on Google search to find one of those 'alternate strategy words'.