Facebook time

Every few years we can see a change in the way we keep up links with others. An era of orkut seems to be fading and facebook and twitter are growing. The same friends with whom I have been keeping in touch through orkut, I am now in touch with them through FB. With time I could see myself having less and less activity on orkut and slowly increased in FB.
Well I am not here to discuss the pros and cons of FB or orkut. The underlying message is that we soon get tired with one setup, and then look for a change , like the way we get tired of one job and then look for another.

It didnt happen to our parents in their time. Why does it happen only to our generation so much. Is our attention span so limited , that a change is imminent every few episodes of time ?

Though the examples on which I am applying these metamorphosis are trivial, but in depth its definitely not a conforting thought.