This means the game itself has sold for over 1 million dollars. Now, I know that doesn't all go to Uber but still that's pretty damn good especially for a first week XBLA
I don't know how the numbers are for Xbox Live but many PC gamers never play their games online. So I would assume that the actual number of sold games is quite a bit higher than the number of players in the leaderboards because blitz-only players won't show up. Unless you are added to the list regardless. Anyway, congrats Uber!
I just bought it from gamestop for a friend (gives you a redemption code) and it was 15$. I guess that means about $1,050,000 total in sales.