The object is to get more points than other people in the world. You can look at how many points your friends got, people in the local area, in your state, in the United States, and in the world. It knows where you are using the GPS in the device (or your IP address from the computer I assume).
In addition, you earn award points for various accomplishments. Out of a possible 1330 points, I've earned 160. For instance, I earned 5 points for the Hot Hand Award, because I got five questions right in a row. Also, I earned the Spicoli, also worth 5 points, for missing five questions in a row. You also earn points for playing in different places. I got the Stud Stache award for playing in five different U.S. states. I soon hope to earn the Road Soda Award (20 points) for playing in 10 states. I'm up to eight states I've played in (including DC as a state)--DC, Virginia, Maryland, New Jersey, New York, Connecticut, Massachusetts, and Maine. I expect to get Delaware, Pennsylvania, and Florida soon. As far as I know, there is absolutely no value to earning these points, but I seem to be obsessed with getting them. I'm not sure why. As all trivia games should be, it is all pointless. I can't stop though.
The only problem with the game is that it is easy to cheat if you're a devious person. If you sign in with a different email address, you get the same questions again when you play as someone else, so its easy to see the answers and get a crazy high score. I'm sure some people do that. They know who they are.
If you want to join the fun, add me as a friend in Qrank. My name on the game is the same as my Twitter name -- Bluespongerun. You can see my scores on Twitter (in my sidebar). I can get more points if I score high among lots of friends... so don't join if you're real smart or plan to cheat.