DALLAS (CNN/Money) – If you're over 30, you're out of place at QuakeCon. Trust me; I've learned this first hand.

But the thousands of young men in their late-teens through mid-20s wandering the show floor at this seventh annual convergence of "Doom" and "Quake" fans are one of the most desirable demographic groups around. And the show's sponsors are working overtime to enhance their street cred with the hardcore gaming crowd, in hopes of major returns in the coming months.

It's not just small, gaming-centric companies who are gathered here in Dallas either. AMD, nVidia, Activision and Linksys (a division of Cisco (CSCO: Research, Estimates)) lead the pack of publicly traded firms who see big dollars amidst the deathmatching.

nVidia's gamble is the largest. The company has ponied up some $125,000 in cash for prizes in the show's various tournaments. That's on top of a licensing fee that ranges somewhere between $25,000 and $50,000 and whatever additional charges it faced in setting up its substantial booth. Additionally, all of the PCs demonstrating "Doom 3" as well as those in the cash tournaments are running nVidia's top-of-the-line GeForceFX video cards.

"Community initiatives are increasingly becoming an important part of nVidia's marketing," said spokesperson Carrie Cowan. "These are the guys who are going out to purchase new products every six months. ... It's a great way to stay in tune with our core community."

nVidia (NVDA: Research, Estimates) is also looking to regain some bragging rights in the gaming community. Last year, when rival ATI (ATYT: Research, Estimates) powered the first public showing of "Doom 3", it hurt nVidia's standing in the gaming community. The mere mention that the multiplayer demonstration of "Doom 3" is running on nVidia cards could help reverse that.

AMD (AMD: Research, Estimates), meanwhile, is locked in its own battle with Intel (INTC: Research, Estimates). The chip manufacturer paid a $25,000 sponsorship fee to be a part of QuakeCon, as well as an additional $100,000 for its booth and other logistics. It's also powering all of the PCs in the tournaments taking place at the show – using $150,000 worth of equipment.

Like nVidia, AMD is looking to gain a competitive edge. It's also looking to promote its 64-bit processor, which will be released next month. The company is counting on hardcore gamers to lead the charge.

"Trade shows are not one of the better marketing return on investment vehicles because they're not focused," said Hal Speed, senior manager of strategic initiatives for AMD. "QuakeCon, because it is focused, is great. Everyone here is our target market. ... Long term, we want to have an affinity program with the people here. Just like Harley Davidson has the hogs, AMD wants the fanboys."

To help establish that program, AMD is asking participants for their email addresses in return for a chance to win t-shirts and hats – and a sizable percentage of the 5,000-plus people at the show have done so.

Linksys is a QuakeCon veteran, with this being the network hub and switch manufacturer's fifth appearance at the show. Its booth is smaller than AMDs or nVidias, but its presence is felt in the "Bring your Own Computer" room, where thousands of people compete on a local area network. Linksys supplies the network hubs that enable people to play together.

"Being here, in front of 4,000-6,000 people, we're meeting the people who are going to go to the store to buy the latest and greatest," said Karen Sohl, a Linksys spokesperson. "If the network [here] goes without a hitch, that sticks in their mind – and when they walk into Best Buy, they remember that and buy our products."

The company also relies on interaction with QuakeCon participants to gauge which products are going to be hot. This year, said Sohl, interest is running high in Gigabit switches and cards – networking devices that allow PCs to talk to each other 10 times faster than today's standard.

Of course of all the QuakeCon sponsors, Activision (ATVI: Research, Estimates) is the one who stands to make the biggest return on its $20,000 sponsorship fee.

After all, it's the company who will be publishing "Doom 3".