US High Street retailer GameStop has said that free-to-play battle royale titles Fortnite and Apex Legends have been key factors in increased digital currency sales.

Speaking to investors, as transcribed by Seeking Alpha, the firm's COO and CFO Robert Lloyd said that digital revenue had risen 4.7 per cent month-for-month and 16.5 per cent year-on-year, largely due to this.

"Digital receipts grew 4.7% in the quarter and 16.5% for the year primarily driven by continued strength in digital currency for free to play games like Fortnite and buy downloadable content," he said."

Executive chairman Daniel DeMatteo added: "In terms of Apex and Fortnite, again, those -- both of those games are continuing to drive sales and digital currency in our stores and continuing to have a positive impact on our accessories sales much like we saw last year."

In the past, research has pointed to 69 per cent of Fortnite players putting their hand in their pocket for in-game items.