He was a writer for 22 Minutes, and one skit in particular was so popular it was turned into a one-hour special as Talking to Americans, attracting 2.7 million viewers across Canada and making it the highest-rated comedy special in the country's history.
Mercer's other CBC show, Made in Canada appeared for five seasons and airs in the USA, France, Austrailia and Latin America.
In Christmas 2003, he made a a one-hour Christmas special called Christmas in Kabul.