The online retail giant debuted coding tools on Monday for developers to tweak their existing video games to contain multiplayer competitions in which they can reward players with in-game and physical prizes, like Amazon’s Echo smart speakers.

The tools, called Amazon GameOn, will be free for developers until May 1. After that, developers must pay a third of a penny each time one of their users plays a tournament (the first 35,000 competitions will be free).

Although Amazon will take an initial financial hit by making the tools temporarily free, Amazon’s head of competitive gaming Marja Koopmans is hopeful that will lead to more developers building games using AWS as the underlying infrastructure.

“We leverage AWS—there’s a flywheel there,” Koopmans said of the ties between Amazon’s video gaming business and its cloud computing unit. “We are peanut butter and jelly, and ice cream and cookie dough.”

One of the biggest problems facing gaming developers, especially those that make mobile games, is retaining players who often lose interest over time, Koopmans explained. She believes that by incorporating competitive tournaments, coders can keep players glued to their games because of the thrill of playing with others.

Koopmans said that these developers should take advantage of the growing popularity of e-sports, or online gaming competitions, which Amazon has been pursuing in recent years. The company hosted an e-sports competition in 2016 that was dedicated to the online battle game Vainglory and another one centered around the popular online fantasy card game Hearthstone the following year.

Developers using Amazon GameOn, which is essentially a collection of coding tools known as APIs, can also link their games to Amazon’s online retail store so that players can receive physical goods as prizes. While gaming publishers can choose some of Amazon’s gadgets like the Echo speakers as prizes, they are also allowed to choose other items from Amazon’s shop, Koopmans explained.

However, these gaming publishers will have to pay for the goods as well as the shipping costs to their players, which in turn helps Amazon’s core e-commerce business. Publishers can also use the tools to create leaderboards that show their players’ overall rankings.

Several gaming publishers are using the new tools, including nWay and its Power Rangers: Legacy Wars mobile game that recently debuted alongside the 2017 Power Rangers movie based on the Power Rangers franchise. Other publishers include Game Insight, Millennial Esports’ Eden Games, Umbrella Games, Nazara Technologies, Mindstorm, Mokuni, Avix, and GameCloud Studios.

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Amazon isn’t the only tech giant that sees big business in online gaming. Just last week, Google partnered with gaming publisher Ubisoft on coding tools that are intended to improve the performance of multiplayer games. Microsoft, which also offers gaming developer tools, also said last week that it is developing a Netflix-for-games like service for consumers, similar to graphics chip maker Nvidia.