Following in the footsteps of Amazon, Toys 'R' Us, and Best Buy, mega-retailer Wal-Mart is dipping its toe into the waters of used game sales, offering titles for sale through its online store -- but not at its brick-and-mortar locations.

The move was widely expected, as Wal-Mart earlier this year installed used game trade-in kiosks within several dozen stores across four states, allowing the company to build up an inventory and creating a seemingly disjointed approach to the used game market, by which the company buys used games through a completely different channel than the one through which it sells them.

Wal-Mart, as well as the other retailers with new used game programs, are likely taking after retailer GameStop, which draws a significant proportion of its revenue from used game sales, and dominates the overall specialty gaming retail market.

Despite the new competition, Wedbush Morgan analyst Michael Pachter, as quoted in a Dow Jones Newswires report, doesn't believe the newcomers will be able to significantly encroach into GameStop's established used game demographic of "[unemployed boys]" -- except possibly Amazon, which Pachter thinks could attract as much as 10 percent of that market.

And earlier this year, EEDAR analyst Jesse Divnich said "GameStop provides a considerably higher value than Amazon" when it comes to used games.

Wal-Mart claims its used games are being sold for up to a 30 percent discount from new game prices, with a three-week quality guarantee.