Microsoft has admitted that its Xbox Game Pass subscription service reduces sales of titles included.

That's according to data submitted to the UK's Competition and Markets Authority (CMA), which indicates that after going into the service, games see a decline in sales. Given the heavily-redacted nature of the CMA's report, it will come as no surprise that the exact percentage of sales decline is not included.

"Microsoft also submitted that its internal analysis shows a [redacted]% decline in base game sales twelve months following their addition on Game Pass," the CMA reported.

This is the exact opposite of what Xbox boss Phil Spencer said back in 2018. At the time, the exec said that Game Pass actually increased sales of the titles included in the subscription service. The following year, Microsoft's head of planning for Game Pass said that the inclusion of Rage and Doom in the service resulted in a 25 per cent increase in pre-orders and a sales rise of ten per cent.

It's entirely possible that that might have been true at the time and that this has shifted over the last four years. 

"When you put a game like Forza Horizon 4 on Game Pass, you instantly have more players of the game, which is actually leading to more sales of the game," Spencer said at the time.

"Some people have questioned that, but when State of Decay 2 launched if you looked in the US at the NPD you saw this game selling really well the month it launched on Game Pass.”