In Williams Pinball you can earn various currencies to upgrade and unlock tables and customization items.

Tickets: 

Ticket can be earned by watching ads, completing challenges, leveling up or they can be exchanged for Zen Coins. Tickets are used when promoting a pinball table to a bigger grade, to refresh the Daily Challenges and to participate in League Play on the Google Play version of the game.

Zen Coin: 

Zen Coins can be earn by leveling up or completing challenges. You can also purchase Zen Coins in the In-game Store if you choose.

Table parts: 

You can earn table parts by playing the Daily Challenges. Table parts are used when promoting a pinball table to a bigger grade.