It is a very clever feature that allows lazy people to appreciate the content with no effort (zero clicks). We got used to seeing upvote links everywhere and tend to ignore it over time, and thus become lazy to click it. Plus there are even websites that ask you for a new "user account" just for the upvote which, further decreases the chances of clicking. With all that, dcurtis increases the chances by actually "making" you upvote, not even with any "clicks". practical.