We are transitioning all canvas game developers away from Facebook Credits to local currency payments by September 12, 2013, 90 days after breaking change announce. The new payments system simplifies the purchase experience for users, improves the performance of the payment flow, and makes it easier for developers to price virtual goods for a global audience. For more information, please see our local currency payments overview.
For games and apps on Facebook.com, people can purchase in-app items using various payment methods including paying with their mobile phone. When users pay with mobile, the item is charged directly to their mobile phone bill (for pre-paid phones, this uses up some of the existing balance).
Mobile Price-points and Shortcut API allows developers to create an optimized and efficient payment flow for users who wish to pay with their mobile phones, to increase revenue and improve conversion from this payment method.
Prices for goods or currency when paid with mobile differ from other payment instruments like credit card or Paypal due to non-continuous price-points as well as markups determined by carriers which vary based on geo and carrier. Hence each country supports a different set of mobile price points, and developers must set their mobile price points on a country-by-country basis.
Through this API, we expose mobile price points for the current user so that developers can query those price points and create virtual currency bundles in their store to match those price points for mobile purchasers.
This will ensure that:
Mobile shows up as an option in the payment flow. For example, if the highest price point for users in Chile who pay by mobile is 10 credits, but your app's lowest currency bundle is 11 Credits, mobile will not show up as a payment option.
The price of goods offered matches available mobile price points. For example, users in Korea may want to purchase a currency bundle at 5 Credits, but may cancel out of the mobile payment flow without purchasing if the closest price point offered is 10 Credits.
The API allows developers to direct their mobile payers directly into the mobile payment flow instead of asking them to pick from a list of payment options. This cuts down the number of steps to pay by mobile and can improve conversion for developers.
Paying by mobile is prevalent in most Western/European markets along with Latin America (e.g. Chile, Brazil) and Asia (e.g. Taiwan, Korea, Malaysia, Philippines) and building an optimized mobile flow can help you improve conversion and increase revenue in these regions.
Especially in countries where you expect to have more mobile paying users, ensure that you prominently display a 'Buy with mobile' button/option to your users so that they know that they can pay with mobile and can be directed directly into the mobile flow which prices the packages in line with mobile price-points for the user.
Once you know that the user wishes to pay with mobile, ensure that you make the right currency packages available to the user. Using the Mobile Price-Points API, we expose mobile price points for the current user so that developers can query those price points and create virtual currency bundles in their store to match those price points for mobile purchasers.
Once you have this data you can price your in-game currency bundles to match the price-points. So for example using the USD price points shown in the API result sample below, you would create bundles at 10 credits, 20 credits, 30 credits etc. all the way up to 500 credits if you desire and price them at 1.00 USD, 1.99 USD, 2.99 USD and up to 49.99 USD respectively.

Pro-Tip : These price-points can vary based on carrier and country, so make sure that you query the price-points per user and create the logic to dynamically generate the packages for that user. Also we often re-evaluate these packages and terms with carriers, so ensure that you refresh these on a regular basis to ensure that you are leveraging on-going improvements we make to these price-points. We allow you to query the price-points for a user with both a user access_token as well as an app access_token so you can cache these and update regularly server-side.
Whether you display all of the mobile price points in a country or just a subset depends on your game and your users. If your game dynamic is to encourage lots of small purchases, you should favor low price points; if your game leans toward heavy players who prefer discounted high-value bundles, you should favor the higher price points. This may affect the availability of mobile in some countries for your game, e.g. if you want to sell high-value bundles to hard-core gamers, the lack of availability of high price points in some countries (e.g. Chile) means users in those countries will have to pay with method like credit card.
After the user selects a particular package you can invoke the pay dialog directly into the mobile flow. This will directly take the user to the mobile flow and by pass all other payment methods.
So for example you will see this dialog which pre-selects the mobile instrument like below:

Without the mobile shortcut, you will see a dialog where the user is given a choice to select the payment instrument they wish to use and then in addition forced to pick the price-point which is different from the price they originally thought they were going to pay.

To get started please refer to our technical how-to doc for the Pay with Mobile APIs.