Jul. 11--Imitation may be the most sincere form of flattery, but when the imitators are Amazon.com, Wal-Mart, Toys R Us and Best Buy, there's no basking in the glow.

GameStop, which has been riding the video-game wave for a decade, has the attention of the big dogs now. What they covet: a piece of the Grapevine retailer's booming used-game business.

The new competitive threat has damaged the value of GameStop's stock, once a Wall Street highflier. At around $20 as of last week, the shares (ticker: GME) are down 38 percent in the past three months.

Analysts still like the company a lot, with 16 of 18 giving "buy" ratings and an average target price of almost $34. GameStop controls an estimated 90 percent of the used-game market, a key reason for the analysts' confidence.

Once viewed as labor-intensive and maybe more trouble than it was worth, the used-game niche has become a growth engine -- just when the industry is being squeezed by a recession and a dearth of hit products.

Used-game sales surged 32 percent in GameStop's latest quarter and accounted for almost half its gross profit. Sales of new games declined slightly, and new gaming consoles generated about half the sales of used goods -- both in total volume and growth rate.

GameStop does more than a little piece of business. It reported almost $2 billion in sales and $70 million in net profit for the three months ended May 2. Compare that with the same quarter three years ago, when it reported $475 million in sales and $10 million in profit.

Little wonder that other retailers are going to school on the growth story. Since March, Toy R Us, Amazon and Wal-Mart have been experimenting with buying used games. Last month, Best Buy jumped in, announcing tests in two states, including Texas.

Those big retailers are using kiosks to scan games and give customers gift cards for other purchases, while Amazon is accepting mail-ins for credit. With their size and clout -- and GameStop's giant market share -- it's easy to imagine the giant retailers getting some of the business.

But their approach is a far cry from what GameStop does. The sales force in its tiny stores is made up of expert gamers, who offer advice to customers about trade-ins and upgrades. A kiosk can't give that kind of feedback.

The company's used products are more than quick turnarounds. In the past year, it refurbished 14 million software disks and 1 million hardware systems at its plant in Grapevine, where nearly 1,000 are employed.