There’s no doubt gift cards are popular.  They’re a billion-dollar industry and growing every year.

“This year, eight out of 10 people will buy a gift card for a friend, a spouse or a relative,” said marketing expert Rich Killian, of RK Incentives.

Killian and University of South Florida professor Jeanette Mena offered some insight on the popularity of gift cards.

“When people don’t have the time or information to find the right gift, they see gift cards as a safe choice, and they’re also very convenient,” Mena said.

Here are some of the most popular these days, according to Killian:  “Amazon, iTunes, gas cards, home improvement, but mostly department stores, such as Walmart and Target.”

Open-ended gift cards from credit card companies that allow you to shop anywhere are also gaining in popularity.

“Flexibility, ease of use, you want your recipient to be happy,” Killian said.

So, who likes to get gift cards?

“People you’re not going to see over the holidays. Think of those relatives that live out of state,” Mena said.  “They’re also great for teenagers. It makes them feel empowered, in control of their shopping.”

On the other hand, Mena says it’s not such a good idea to give them to a spouse.

“In that context, gift cards seem thoughtless and impersonal," she said. "They don’t require a lot of effort.”

On the good side, generally, you no longer have to worry about gift cards going to waste, thanks to a law Congress passed in 2009.

“It told merchants there will be no more expiration dates," Killian said. "So now, 98 percent of US merchants have zero expiration dates. They’re good forever."

For the most part, people like to give and get gift cards.  The National Retail Federation says they are “the most” sought after gift for the ninth straight holiday season.

Surveys also show that men tend to give gift cards more often than women.  To learn more about the most popular gift cards, click here.