Chell said the drink was an immediate hit with the restaurant's patrons, claiming it "took off like a rocket". Within five years of its introduction, the Caesar had become Calgary's most popular mixed drink. It spread throughout Western Canada, then to the east. Coinciding with its 40th anniversary, a petition was launched in 2009 in the hopes of having the Caesar named the nation's official mixed drink. In Calgary, Mayor Dave Bronconnier celebrated the drink's anniversary by declaring May 13, 2009, as Caesar Day in the city.
The Mott's company was independently developing Clamato, a mixture of clam and tomato juices, at the same time the Caesar was invented. Sales of Clamato were initially slow: Mott's sold only 500 cases of Clamato in 1970, but sales consistently increased after the company's distributors discovered Chell's drink. By 1994, 70% of Mott's Clamato sales in Canada were made to mix Caesars, while half of all Clamato sales were made in Western Canada. Motts claims that the Caesar is the most popular mixed drink in Canada, estimating that over 350 million Caesars are consumed every year.
In the United States, the Caesar is typically available at bars along the Canada–United States border. Elsewhere, bartenders will frequently offer a Bloody Mary in its place. In Europe, the drink can be found wherever there are higher concentrations of Canadians. The drink's anonymity outside Canada has continued in spite of concerted marketing efforts. Producers of clam-tomato juices have speculated that their beverages have been hampered by what they describe as the "clam barrier". They have found that consumers in the United States fear that there is too much clam in the beverages.
While Mott's Clamato continues to be synonymous with the cocktail, other producers have begun offering alternative Caesar mixes. Walter Caesar (named in honor of Chell) was launched in 2013 to offer an 'all-natural' alternative to Clamato. Walter Caesar also became the first Caesar mix in Canada to be approved by Ocean Wise by using ocean-friendly clam juice from the North Atlantic.
The Caesar is popular as a hangover "cure", though its effectiveness has been questioned. A study by the University of Toronto released in 1985 showed that drinking a Caesar when taking aspirin could help protect a person's stomach from the damage aspirin causes, as compared with drinking plain tomato juice.
Mott's holds an annual "Best Caesar in Town" competition as part of the Prince Edward Island International Shellfish Festival. Contests held across Canada to celebrate the cocktail's 40th anniversary in 2009 encouraged variants that featured the glass rimmed with Tim Hortons coffee grinds, Caesars with maple syrup, and Caesars with bacon-infused vodka.