As video games become spectator events, it’s changing how they’re marketed and designed

The rise of online audiences watching video gamers stream their games as they play isn’t simply a new form of entertainment seen by millions. It’s also driving video game sales, and, in the US, drawing the attention of federal regulators.

A recent studyby live streaming company Twitch attributed 25 per cent of sales of releases like the fighting simulator Punch Club and the kill-or-be-killed multiplayer game The Culling to those games being played on Twitch. The study found that viewers were more likely to buy a game within 24 hours of watching a stream of the game in action.

Facebook and Blizzard getting into the game-streaming business

“There’s a clear relationship between viewing and purchasing behaviour,” said Twitch data scientist Danny Hernandez, who studied users who connected their Twitch account to online game retailer Steam for increased social interaction.

It’s not only the most popular online players who influence sales. Hernandez found that mid-tier Twitch streamers – those with audiences between 33 and 3,333 concurrent viewers – are responsible for 46 per cent of game sales.

While the majority of online gamers freely stream themselves playing, many of the most popular streamers with millions of followers are now regularly paid or sponsored by game publishers, a practice that was recently investigated in the US by the Federal Trade Commission.

The FTC saidthis month that Warner Bros. will settle charges it deceived consumers by not properly disclosing it paid influencers with big followings on YouTube to promote the action game Middle-earth: Shadow of Mordor in 2014.