(RNN) - Advertisers will spend up to $7 billion dollars by 2019 on ads in video games, but your kids may be seeing way more than you realize - secret, unbranded placements of products inside those games.
Some games let you know on the label, but many do not.
When Marina Spriggs' teenage son Joe wanted to play a crash 'em up car stealing video game, she did her research.
"I'm smart enough to know to talk to my child about the content that's in there," she said.
But even she was surprised when we told her about an option in the game.
"I had no idea that the game contained smoking at all," said Spriggs
In one study, 42 percent of video games reviewed contained tobacco images, but only eight percent of those had tobacco-related content descriptors on the warning label.
"People should know that the smoking depictions have the potential to drive behavior," said Dave Dobbins.
Dobbins is with the anti-tobacco group Truth Initiative. He says there is scientific evidence that exposure to smoking in movies can influence teen smoking.
Truth Initiative showed a group of teens smoking scenes in a variety of games and asked them if the smoking would influence their behavior:
Participant in study: "I think having their favorite character smoking definitely can affect whether or not they become smokers later in life."
All of the games the kids looked at were rated "M" for mature. Some contained the tobacco marking; some did not.
Marina's son Joe, who says he doesn't ever use the smoking in his rated-m game, thinks the option is unnecessary.
"I think it's really unnecessary," he said, "There's no real - what's the point of it?"
The Entertainment Software Rating Board says it uses more than 30 different descriptors.
"It should not be surprising to find the tobacco content descriptor may not be included for titles that are rated 'M' or mature for ages 17 and older."
The group stresses that games rated 'T' for teen or lower are assigned the tobacco label.
But Truth Initiative wants all games containing tobacco to be rated 'M' and to be clearly marked.
Dobbins, who stresses that he loves video games himself, says the main mission goes beyond ratings.
"That's not really about ratings as much as it's about education," he said. "It's building consumer demand for tobacco-free video games."
The American Cancer Society says it wants stronger controls on this industry and strongly assumes video games have an effect on youth behavior including tobacco use.
The Tobacco Merchants Association did not reply to interview attempts by the Raycom News Network.