SimonTheBeetle:
Alright, it looks interesting, but I don't understand how it works.
How do you tier up to maximize and get your prizes?
If you spend the 7999 credits, you not only get the bonuses in tier 8, but you also get the bonuses in all the other tiers as well. Any tier you hit, you receive those and all the lower bonuses.
Tap In Rewards is one of the best deals you can get. IMHO