Amazon.com's video-game streaming site Twitch Interactive will begin selling games and features in the coming months, as the e-commerce giant is pushing deeper into $100 billion online gaming industry.

Twitch streams competitions featuring professional gamers, letting viewers chat alongside the action, react with emojis and pose questions. The site now will let its viewers download games and game features such as characters, weapons and tools while they watch their favorite streamers.

Twitch, which is free to watch, generates revenue from selling advertising and subscriptions. Subscribers pay $5 a month per channel to interact with their favorite streamers in chat rooms and get access to emoticons.

Selling features on Twitch will be popular with game developers. For example, League of Legends maker Riot Games Inc. pulls in more than $1 billion a year by selling features for the popular free game.

Amazon purchased the streaming site for about $1 billion in 2014 and sees the platform as a gateway to the market to rival Microsoft and Sony. The company's cloud-computing division Amazon Web Services is also introducing new tools for game developers to host multiplayer online games with speedy connections.

In September, Twitch announced some of its video-game streaming services would be included in Amazon's $99-a-year Prime membership, which also includes delivery discounts and video and music streaming.