While not all of the games currently available in Google+ are attempting to monetize, Kabam’s Edgeworld monetization flow serves as a model for the same basic flow for payments in games on the Google+ Platform.

As we’ve previously reported, Google+ utilizes Google Checkout for its in-app purchases, meaning game developers (currently) only pay 5% on each transaction to the platform. It also means social games customers on Google+ can only make purchases using credit cards, debit cards, or gift cards branded by American Express, Discover, MasterCard, Visa, or Visa Electron.

By contrast, Facebook (and many other online games services) have either partnered with and aggregated many other payment methods around the world or simply partnered with local payment aggregators, but Google has not confirmed plans to integrate additional payment methods yet. For now, there is no PayPal, no mobile payment options, no prepaid cards, etc.

Edgeworld monetizes through the sale of a premium currency, Platinum, which can be spent on gameplay boosts and defenses. The game starts all players off with 10 Platinum and does not currently provide any means of earning Platinum either through gameplay or by completing promotional activities (e.g. offer walls, video ads, etc.). To buy Platinum, players must select the Get Platinum tab from the upper menu of the game screen, or click Add next to the Platinum icon in-game.

Selecting the Buy options opens a pop-up window, prompting the user to sign into Google Checkout:

Clicking Start Now either sends the user to a Complete Purchase screen, or to the following screen if the user hasn’t already associated a credit card in their Google Checkout account:

The Complete Your Purchase screen appears automatically when the user is already signed into a Google Checkout account with a linked credit card:

And then a Thank You screen appear after completing each purchase:

That’s it. The currency purchased immediately appears in the user’s in-game wallet (orange circle added for emphasis):

We’ll be tracking the payment flow and payment method options Google rolls out as part of its wider Google+ Games launch over the coming weeks.