Google Play Points: Join for Free and Earn 1+ Points Per $1 Spent (100pts = $1 Google Play Credit or In-Game = 50% Discount)

Haven't seen this one before -

• Earn points on everything you buy, including in-app items. Up to 4x points during special points events. Use points for special items in games, or Google Play Credit.
• Start out earning 1 point for every $1 you spend on in-app purchases, apps, games, movies, books, subscriptions, and more with Play.
• Earn up to 4x points during special events. Get bonus points for trying featured apps and games.
• Redeem your points for discounts and special items like characters, gems, and more in some of your favorite apps and games.
• You can also redeem points for Google Play Credit to use on anything, including games, apps, movies, and books.
• There are 4 levels. The higher your level, the more points you earn on everything you buy.
• Certain levels have access to weekly special prizes that get better with each level.
• When you reach a new level, you keep it for the current and following calendar year.

I signed up and here are some example deals they offered me. It seems that using point for in-game items is most cost-effective (if you were going to spend that money anyway) as it gives you a 50% discount -

Special earn rates - The highest earn rate will be applied
Welcome offer: 3 points for every $1 for your first 7 days - Ends Nov 5
Angry Birds Dream Blast - Toon Bird Bubble Puzzle - Ends Nov 1 - 6/$1
DreamWorks Trolls Pop: Bubble Shooter & Collection - Ends Nov 1 - 6/$1
Captain Tsubasa: Dream Team - Ends Nov 1 - 5/$1

Spending points
Google Play Credit costs 100 points for $1
Candy Crush Saga $5 coupon - Estimated value: 500 points ($5.00) - Cost 250
Lords Mobile: Kingdom Wars - Happy Hour x5 - Estimated value: 360 points ($3.60) - Cost 180