Button is the one of the my favourite position in tournament. Raisin on the button depends of tournaments ti. in wich stage tournament is. In early phase raising on the button does not have meaning. In middle and especially late phase of tournaments raising on the button is the good move. Best situation for raising the button is that: everyone fold before you, tournament is one the late phase, players on SB and BB have less chips than you. This is the perfect situation for raise and you should raise.