Also, you can just keep playing as normal. All the tracking is automated with your gamercard as well, so no hassle. So it's not like you need to spend all this extra money if you do not want to. You can just play as normal and join a casual team for GSL.
Basically GamerScore League (GSL) is a on-site competition where you will sign up on a team of four people, and your team will compete against all of the other teams on how much gamerscore your team puts up compared to all the rest. However, this year there is a twist. We are going to be in a competition with our sister site PS3T too. You can only participate in the competition against PS3t if you are signed up for GSL however. That will be a competition based on the amount of achievements our site scores versus the amount of trophies their site scores. And there will be an even amount of teams so no need to worry about that. We need as many good achievement hunters as we can, so I encourage you to get a good team!