Almost immediately after Walmart announced that it is entering the used-game industry, GameStop's stock shared plunged by five percent last Tuesday, March 18, USA Today reported.

The retail giant's trade-in program will allow customer to bring in old videogames in exchange for store credit in all of its 3,100 branches or at Sam's Club. In Walmart's blog, Justin Williamson, director of entertainment wrote, "Our strategy is to pay more for used games, sell new and used games for less, and give our customers the flexibility to spend their money how they want."

However, with Walmart's new offering, they are in direct completion with GameStop, the biggest seller of used games in the United States, according to the NY Times. In fact, the company's used-game products accounts for more than 27 percent of their total sales, which is roughly around $2.4 billion.

At first, GameStop was feeling confident regarding Walmart's decision to enter the same industry, stating that it has emerged victorious against larger competitors, Dallas Sun reported. In a press statement, the game retailer said, "We have faced many competitions in the past who have tried to enter the buy-sell-trade model, and GameStop has continued to come out on top. Given our expertise, we will continue to win the battled. We've beat out other large retailers when they've entered the category."

And now, it seems GameStop is already feeling the effects of Walmart's presence in the industry even though its trade-in program hasn't even started yet. But this isn't the first time the game retailer's stocks plummeted because of Walmart. In December of 2009, GameStop's shares dropped by almost 9 percent after Walmart slashed its videogame prices by 15 to 20 percent as part of its holiday deal, Kotaku reported.  

Walmart's trade-in program will begin on March 26. Games designed for the Wii, Xbox, and PlayStation 4 can be traded for eGift cards which can be used to "purchase anything sold at Walmart and Sam's Club, both in stores and online."

So, who do you think offers a better used-game service? Let us know!