Newgrounds.com — Everything, By Everyone.

Because it's not good enough to have 4 stars, obviously???

Actually the real reason it has 3 is because Newgrounds gives experience points to people who vote on games, which means to farm experience points people will go to games and give "dummy votes" on them to get points. Generally the vote they give will be the same as the current star rating, which means once my score settles to about a 3, there's no going back.