Canadians sound very similar to people in the US. That allows many singers, actors, announcers and more to cross the border physically or virtually and not be seen as different. Since the US has ten times greater population, their market has more absolute dollars to spend.
For most things relating to communications like for elite singers, actors, announcers, Canadians can cross borders to gain more financial success in the US or other English or French speaking countries. They can fish where there are more fish. The list is long from Celine Dion, Neil Young, Shania Twain, the Ryans, all the way back to Mary Pickford.
Like many things, crossing borders works both ways. Advertising spills from Canadian sources into the US and vice versa. With the population disparity, the US media gains more revenue from this than Canadian media do. There are border US TV stations whose business is reliant on Canadian advertisers. International spill is even easier today with digital media.
Many brands are marketed both in the US and Canada using the same name and virtually the same graphic presentation. Viewers are not even sure where the message is coming from.
For many years I worked with major US head officed companies marketing their brands in Canada. One extremely efficient communications tool for the Canadian subsidiary was easily and inexpensively importing of television commercials. It is kind of an invisible subsidy for US companies in Canada because the expense of the commercial production was already paid for.
The cost of developing and producing advertising is an overhead cost that can be hundreds of thousands of dollars. Most consumer brands would rarely spend more than 10% of their budgets on production. Imagine if it were reduced through a gift from head office?

That is not to say that commercials done in one country are appropriate to use in another. However, the savings, especially for a smaller country, are very significant. There are no tariffs or duties in something delivered over the airwaves.
Some countries require commercials to be produced in country, like Venezuela where I personally worked. This is to protect local production jobs. Canada and the US have no such rules. Canada does require a percentage of music be Canadian for radio play based on the MAPL (Music, Artist, Performance and Lyrics) rules. It sometimes leads to weird interpretations, but let’s not discuss that here.
To use an already produced imported commercial, there are a few conditions that make it possible for the brand: having same name, same creative strategy, nothing inaccurate or illegal in the copy, and nothing culturally inappropriate. Almost all major brands fit the first two.
So where are the hiccups to this free ride? Or is it that easy?
Packaging can be an issue. Canadian packaging, as mentioned in the recent trade talks with the US, requires bilingual messaging. Both French and English must be shown. TV commercials used to be shot with “hero” packaging that removed all the small print (weight, disclaimers, legal copy) to allow focus on the brand name. That is an easy change in this age of digital. A bilingual Canadian package can digitally replace the US package, or vice versa.
Normally the rights to use music, likenesses, and talent are limited by country. Talent is rarely signed for international use and must be paid according to union definitions. Few US advertisers consider that commercials will be used in other countries unless they are featuring an international celebrity – and not always even then.
I have had experience where it was less expensive to record a music track from scratch rather than pick up the rights to the US commercial track. So no savings there.
When we imported US creative, we would have to pay the performers based on US agreements. When we shot in Canada, we could shoot with union talent or with non-union. Union talent was usually more profession and did a better job, but they cost more. Non-union talent was sufficient when the acting requirements were not demanding.
Product claims is a much more difficult area to manage. In the US, networks approve the claims and you can leverage on network versus another. That allows for broader claims that stretch into the grey area.
In Canada, with food products, Consumer and Corporate Affairs (CCA) or its nominees, review them as if the claims were on packaging. Many claims allowed in the US are not permitted in Canada when they are judged to be questionable or misleading. Some actions are also not allowed in Canada, such as “trash canning’ competition. One unique case where a visual was not allowed that I encountered was with Fruit Roll-ups. The US commercial had a child making a ball of the product and tossing it up in the air to catch in their mouth. In Canada, this was judged to be a dangerous activity since the ball could lodge in a child’s small throat. We were required to eliminate that edit.
I have led many negotiations with CCA to adjust US produced creative to make it appropriate for Canadian viewers. For example, Subway did a lot of US creative that focused on weight loss. Canada has regulations that require nutrient control for weight loss programs, not just use of a product. As a quick serve restaurant Subway had no such controls or regulated programs. A sandwich advertised as “low in fat” could end up with the customer requesting mayonnaise and cheese to be added to give it quite a high fat content. This meant for Canadian audiences we had to revise and redo the announcer descriptions and sometimes add legal supers. Canadian regulations are usually a lot more consumer protection on any health claims or benefits.
The most difficult Subway approval we achieved was for the tag line they began in the early 2000s, “Eat Fresh” which was totally okay in the US. While the bread and veggies are reasonably fresh, ingredients like cheese, sausages, meats, pickles, and most sauces could not be fresh. I negotiated with CCA, arguing that each sandwich was prepared fresh. With that they agreed that we could use the system wide tagline only if we provided a super explaining that by “fresh” we meant prepared fresh. The slogan was a huge success; we adapted it for our Subway #breakfast sandwich launch as “Start Fresh.” In the most Canadian of cross border adaptations, for a hockey sponsorship, we had it painted it on the side of the Zamboni that cleaned the ice between periods as “Ice Fresh.”

It was also helpful to find US creative where there was no actor talking on screen. For those we could record our own tracks with the copy that was acceptable in English or in French. With a smaller population, French production was a greater burden on our budgets.
Our Canadian commercials for Subway were run in the US, Australia and New Zealand; so, it is not a one-way street. The financial benefit, however, is greater for smaller markets to use large market creative. Ad production is an overhead cost.
Plus, if a US brand advertises heavily, cross border spill from US stations benefits the Canadian version of the brand.
Less often there are dialect changes to take note of – using napkin instead of serviette, using “zee” instead of “zed” as examples. Take note of that La Zed Boy furniture.