Travel Michigan will soon be targeting Toronto shoppers in an effort to get them to spend their money in the state.

"Toronto is a great potential market for us. There is a huge number of upper- and middle-income consumers there," said George Zimmerman, vice president of Travel Michigan. "Canadians are great travellers and travel here often. But for budget reasons, we haven't focused on Toronto in the past."

Zimmerman said billboards around southwestern Ontario, urging consumers to "Shop Detroit" have been a success, and it's now time to expand. He called Toronto "a natural target."

"We're competing against Buffalo and other U.S. destinations, as well. Reminding Canadians that Michigan is a great destination for shopping, we see [it] as a way to get more Canadian traffic and dollars than other states," Zimmerman said.

Billboards appear as near as Windsor and as far east as Kitchener-Waterloo already. Zimmerman said the campaign is drawing "a huge number of Canadians" to Michigan.

"We don't have final numbers from last year, but everything we hear anecdotally is very positive," he said.

The increase may also have to do with duty-free changes introduced by Ottawa in the 2012 federal budget. The duty-free limit on visits longer than 24 hours rose from $50 to $200, effective June 1, 2012.

As well, any visit longer than 48 hours allows Canadians to return with duty-free goods worth up to $800. That's an increase from the previous rules of $400 for up to a week, and $750 for longer than a week.

For stays of less than 24 hours, there's no change: the allowance for duty-free goods remains at zero.

"We think Canadians are aware of the increase in what they can bring back, and it means more Canadians in Michigan," Zimmerman said.

The number of Canadians who made overnight trips to the United States hit a record high in December.

Statistics Canada said there were nearly two million overnight trips to the United States, the highest level since record-keeping began 40 years ago. There were also 2.7 million same-day car trips to the United States.

In total, there were 4.7 million trips to the United States from Canada, an increase of 1.8 per cent.

Zimmerman said Canadians, more than any other nationality visiting America, rate shopping as one of the primary reasons to visit.

"Shopping is always on the agenda of Canadians when they're in the U.S. Shopping is a component of every trip people take. But it seems to be much more of a motivation for Canadians," Zimmerman said. "With Canadians, we see shopping is a primary motivator."

Many brand-name products still cost 35 to 40 per cent more in Canada compared to the United States, even though the loonie was above parity for most of last year.

Earlier this year, senators who studied why Canadians pay more than Americans for many products called on the government to review the taxes on imported goods.

"Canadians, like Americans, are looking for good deals and new experiences," Zimmerman said. "I think it's reciprocal, though. We certainly come to Canada for experiences, as well."

Travel to Canada from the United States rose 1.7 per cent to 1.7 million trips in December.