When it comes to etymology, gotta agree with Ben.
Chain dropper, like in chain smoker, goes through a lot of ciggies, but still only one at a time.
They light the one from the end of the other, like the links in a chain.
The power dropper, to use the same smoking anaology, are more like this lady....
Chain droppers are more likely to read your content. A lot of them are using Entrecard, and this method of dropping, to discover random new blogs that may interest them.
Banding them into the same category as power droppers is not giving them enough credit.
I have nothing against power dropping, I have been know to do a little myself.