So is the amount of money they budgeted for betting and spent eating and shopping.

But it's too early to lay odds on whether the wagering uptick is an anomaly or a new trend for a destination that lately has seen more growth in shopping and dining than gambling.

The tidbit on visitors' gambling habits was just one among hundreds of informative nuggets in the latest edition of the Las Vegas Visitor Profile Study. The survey is the result of 3,600 personal interviews conducted in 2006. The results were compared to surveys from 2003, 2004 and 2005

The study, released Tuesday, reported that 11 percent of respondents said gambling was their primary reason for visiting Las Vegas, up from 5 percent in 2005.

The Las Vegas Convention and Visitors Authority has sponsored the study for 32 years, making it one of the most consistent sources of publicly accessible information about why people visit Las Vegas and what they do during their trips.

"Certain things change; certain things we don't want to change," said Kevin Bagger, director of Internet marketing and research for the authority.

The gambling nugget, for example, defies a recent trend in which 5 percent or fewer of the respondents said betting was the main reason they came to Las Vegas.

"If there is one year that changes, we have to see if it evolves into a trend over time," Bagger said.

The mean amount of money people budgeted for gambling in 2006 was $652, an increase of slightly more than $25, or about the cost of one hand of blackjack at many tables on the Strip.

Average spending per trip on food and drink increased more than $12 to nearly $261.

On a scale of one to five, leisure visitors ranked dining, gambling and gawking at resorts in a statistical dead heat in importance in their decision to visit Las Vegas. Shows, shopping, clubs, spas and golf followed.

Responses from convention and trade show attendees indicated the mere fact their event was in Las Vegas prompted them to actually attend.

Among respondents who came for a trade show or convention, 48 percent said that show was in Las Vegas influenced their decision to attend.

"The brand of Las Vegas is a selling point," Bagger said. "People want to come to the destination, that will support their attendance."

The number of people from households with six-figure incomes who visit Las Vegas is also on the increase. It was 24 percent in the latest survey and 10 percent in 2003.

That trend is driving the development of new multibillion-dollar resorts on the Strip, such as the $7.4 billion CityCenter by MGM Mirage and the $4.4 billion Echelon by Boyd Gaming, a company that previously focused on more value-oriented Las Vegas customers.

"It is our entrance into the luxury tier," said Boyd Gaming spokesman Rob Stillwell. "Until Borgata (Boyd's Atlantic City luxury resort that opened in 2003), that hadn't been part of our customer demographic."

The amount of money people spent during their Las Vegas trips also increased in 2006, although not by much in some categories.

The amount spent shopping increased just $4 per person to about $141, much less than the 2004 increase of more than $27 or the 2005 increase of more than $12.

And when the shopping results are narrowed to include only people who shopped during their trip, the per person spending decreased $14 to $206.

"I would imagine people have less disposable income to spend in Vegas," said Michael Kammerling, senior vice president of retail at Grubb & Ellis in Las Vegas.

Kammerling said perhaps rising energy costs and economic uncertainty are making people less willing to open their wallets.

"I would probably want to wait another year before coming to any conclusions," Kammerling said.