Earn triple Starpoints on stays including a Thursday or Sunday night, all other stays earn double Starpoints. This new promotion from Starwood starts today and goes through November 15.
You must register for this promotion. Here is the link. Extra Starpoints

FINE PRINT – Check the list on the link for all of the properties excluded from this promotion.
Starwood members earn four total Starpoints per eligible US$1 spent for the double promotion. An elite member will continue to earn a 50% Starpoints bonus on his or her base earnings; this equals five Starpoints per US$1 spent for the double promotion.

Starwood members earn six total Starpoints per eligible US$1 spent for the triple promotion. An elite member will continue to earn a 50% Starpoints bonus on his or her base earnings; this equals seven Starpoints per US$1 spent for the triple promotion.