The programs of political parties are extensive, and the number of speeches that candidates give is enormous. As a consequence it's hard to keep track of which candidate's program is best reflecting your personal ideas. This is the reason that a number of years ago in the Netherlands, the website stemwijzer (vote-wiser/pointer, pun intended I guess...) was started. By answering a number of position statements, you could determine the party that best reflected your ideas.
The idea has been refined and copied by several institutes, and now there is also an electoral compass for the US presidential elections, initiated by the Dutch newspaper De Volkskrant and the Wall Street Journal. In it's first month it attracted over a million visitors, and I'm guessing those are not solely from The Netherlands.
In terms of usability, the system allows you to effectively and efficiently determine your position in the political landscape. Although, it should be said none of the position statements is about whether you 'like the guy'. Or girl. So I guess they left out the satisfaction component of the usability definition.

PS just discovered that stemwijzer also developed a US version: votematch USA.