You can earn free SPG miles for answering trivia questions from Audience Rewards. Two miles each.
SPG is a great loyalty program as you can transfer to other frequent flyer programs to prevent your miles in your account from being expired.
Here are some of the updated answers for July 2013.
Answers are: 1. Seattle 2. 1 3. Cabaret 4. False 5. 1975 5. Masha.
Source: http://thefreebieblogger.com/113710/12-free-best-buydeltaus-airwaysstarwood-reward-points/