What changed? The power of San Diego Comic-Con International. While the annual event for all things sci-fi and fantasy has been taking place since 1970, in recent years it has attracted movie, TV and video game fans who come looking for the latest dish on what they’ll be watching and playing in the months to come. It is where directors preview upcoming movies and TV shows. Now, conventions like it have become crucial for companies launching new products as well.

Instead of unveiling all its products at industry only events, such as New York’s American International Toy Fair in February, LEGO opted this year to save something for the faithful. “Why you’re seeing this paradigm shift is really because of the fans ability to spread news,” says Scott Steinberg, principal analyst for TechSavvy Global. “They talk in blogs, post on social media and generally spread the news. That voice is more powerful than ever, so for many companies there is no reason to announce it at a closed event anymore.”

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As a result fan conventions are now blurring the line with industry trade shows. News that was released in an official press conference with vetted reporters is instead provided — more profitably — directly to diehard fans. It’s a matter of going to where the target audience is says Linda Musgrove, author of The Complete Idiot’s Guide to Trade Shows. “With those products that appeal to the fan base it makes sense,” she says. “At industry shows you get caught up with competitors where at a convention with a core fan-base you can stand out a little more.”

As a result many companies are re-evaluating at the convention circuit, whether the various Comic-Cons that are held throughout the United States or events such as this week’s QuakeCon video game convention, which has grown in size from around 1,100 attendees in 1996 to nearly 10,000 today. Most are hardcore gamers. Instead of traveling to Europe for a week’s vacation, these fans often drive Dallas, Texas to take part in three days of intense gaming and discussion of gaming.

For video game companies this is practically a captive audience. “Shows like QuakeCon offer fans an opportunity to get their hands on the new games we have coming out,” says Pete Hines, vice president of PR and Marketing at Bethesda Softworks, maker of the hit game Skyrim.

While companies go to the shows to generate buzz, conventions have additional advantages. Namely, these aren’t trade shows. With nearly 47,000 attendees at last year’s Electronic Entertainment Expo trade show, it can be difficult for companies to break out. “At traditional trade shows such as the CTIA Wireless Show, E3 and the Consumer Electronics Show many companies are jockeying for attention,” says Steinberg.

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Still, some of the conventions are now bigger than many trade shows — at least in number of attendees. San Diego’s Comic-Con started small, but has steadily grown over the years reaching almost 130,000 attendees. With those numbers it actually only is closing in on the Consumer Electronics Show — the largest trade event in North America — which attracted a record 153,000 in January.

That poses a risk, including long lines, crowded conference rooms and a less time to talk to excited fans about new products. Some companies have begun going to both. “Nintendo has been going to the Comic Cons in San Diego as well as the smaller one in New York regularly and this is part of their marketing,” says Billy Pidgeon of M2 Research. “Every year at [QuakeCon], we host a short technology session followed by a crazy and fun fan giveaway,” said Bryan Del Rizzo, Nvidia spokesperson. “In July, we did PDX LAN up in Portland, and at the end of August we will be heading up to Seattle to do Penny Arcade Expo (PAX).”