Is Sharing like 'Gifting'?

It's not what you give, it's what your gift says about you that counts. (Image: George Eastmant House /Hulton /Getty)

Alan Cann in a recent blog asked the rhetorical question: Why would I want to share? -- it was asked in the educational context of students/academics sharing their work. This reminded me of a NewScientist article by Geoffrey Miller about what really motivates some of us to flash our cash. It would seem this behaviour "is engendered by motives of costly signalling to display our personal qualities to potential mates and other social partners"

Is sharing a 'display' -- like the peacock' tail -- a behaviour shaped over aeons of evolution to attract potential friends and more importantly - mates? Is sharing on Facebook a prime example of this?

Therefore: why would I want to share? To make friends and influence people (make some whuffie) and 'to pull in the birds'.