I'd like to invite you over to one of my favourite browser games called E-sim:
E-sim is an society- and war simulator game which started a year ago. In this game each player prepresents one of the eWorlds citizens who can participate in politics (a player can join a political party and seek to be the Chairman of the party, or to try and be a politician and take part in the closure of the laws, or even try to be president and lead to an entire country), join military unit or army and a lot of other things which you should find out yourself.
The game requires only a few minutes of your day to train/work and fight. It is however fully up to you wether you just watch the developing situations or if you will try to actually take part and change the course of the game.
If you are still reading i'm going to take it you want to try out this game. But before i give you the link i want to talk about the referral system.
This game supports a system where you can invite friends to come play and enjoy the game with you. What makes this system interesting is that it gives both the referrer and the taker a bonus. I get 5 gold (The basic currency in the game. Each country has their own currency) for referring you and you get 2 gold once you reach level 7. ( That took me about 2 days which equals 10 to 15 minutes of playing)