tedster - 8:34 pm on Feb 26, 2013 (gmt 0)
It is this damping factor that causes a link's PageRank/link juice to decay or dissipate roughly 10-15%.
There's another part to this. According to the original formula, PageRank calculation is not once and done. It is iterated (repeated) indefinitely around the web until the values stop changing on each round - that is, the number stays the same up to a certain number of decimal points.
Without a damping factor, PR values would never stabilize like that.