GameStop has begun to sell prepaid cards for Valve, the hugely popular games distribution and sales platform. Some interesting discussions probably went into this agreement, since it wasn’t long ago that the two companies were seen as rivals.

Valve has more than 40 million account holders. GameStop has over 4,400 physical stores in an economy that is challenging to retailers. The deal provides Valve’s members an additional way to pay without the need for a credit card, which is particularly important to younger consumers, and gives GameStop another reason for gamers to come in, spend money, and maybe buy other items while they’re there.

The prepaid Valve cards are called Steam Wallet, and GameStop will be selling them in $20 and $50 denominations.

Adding to the can’t-beat-‘em-join-‘em vibe is the fact that GameStop purchased Stardock’s Impulse digitial distribution platform in March 2011, so it already has its own way of selling digital games to consumers.

Steve Nix, GameStop’s general manager of Digital Distribution, issued the following statement: “We are thrilled to be partnering with Valve on this new initiative. This gives even more options to customers now that they can put money in their Steam Wallet using cash, gift cards or trade credits through our convenient neighborhood locations.”

Related links:

GameStop – press release

GameStop – Steam Wallet page

Gamasutra – GameStop partners with digital competitor Valve, offers Steam codes in-store

Ars Technica – GameStop to sell Steam Wallet cards in-store

Forbes – Gamestop Cedes to Steam and Starts Selling Its Vouchers