It lets enthusiastic people express their enthusiasm without overriding the crowd's preference.
Someone who is very knowledgeable or passionate can keep upvoting, but as their voting power dampens new voters will quickly overwhelm their vote. So it strikes a nice balance between leveraging people's passion and the wisdom of crowds.
I'm working on a bookmarking tool/web clipper that let's you organize sites you save by the search you used to find it. No tags or folders.
knovigator.com