Paul LaVoie was inspired by the famous ad man, Jay Chiat, who once asked: “How big do we have to get before we get bad?”

Mr. LaVoie, founder and chief creative officer of the hip, new advertising boutique called Taxi, believes the answer to Mr. Chiat’s question is 150.

“When a certain African tribe reaches 150 people, it sends two of its leaders out to start another tribe,” he said in a recent interview. “The United States Army never has more soldiers in a unit than 150 or else it’s dysfunctional. And dysfunctional in military terms means dangerous.”

He took his epiphany to the bank and two years ago left his Canadian agency behind with its 150 employees in order to start another ‘tribe.’

“It was time to go and I asked myself where I wanted to live. New York City, of course,” he said.

Almost immediately, Taxi NYC and Mr. LaVoie made a splash. The firm is moving into bigger premises and has actually turned down business. For his part, Mr. LaVoie just became President of New York Art Directors, an 85-year-old club that counted Walt Disney as a member.

“I love New York. It has great attitude and anything is possible. It’s friendly,” he said. Mr. LaVoie, a native of Quebec City, started Taxi after being creative director of Cossette in Montreal. Then he moved to Toronto. Then he felt he needed to go.

“Taxi Canada has really taken off since I left. Maybe I should leave New York quickly too,” he said.

Taxi began in 1992 and the name was chosen because it was unique, but also symbolic. “You can only get four people into a taxi and there’s more accountability in a small group,” he said.

Mr. LaVoie said that solving a big problem requires holistic thinking. “Ad agencies can be ghettoes. You don’t make big things in ghettoes. You need clear focus and collaboration, good ‘mojo’ with the client and only three or four people involved,” he said.

Taxi was also different because it was art- and design-driven. “We started by merging design and advertising and got involved in client packaging, retail space design,” he said.

Success came immediately to Taxi NYC, which is surprising. Unlike other agencies, Taxi’s New York office was not opened strictly to serve an existing Canadian client but rather to tap into fresh business.

“Most advertising agencies go to new countries on behalf of their clients. The problem with Canada is that we don’t have global brands, apart from Four Seasons, BlackBerry or Cirque du Soleil,” he said.

So far, the gamble paid off for him and his 10 Canadian partners. Mr. Lavoie said the firm is up to $100 million in billings and was profitable in its first year. The tiny start-up’s first big American gig was to re-brand College Sports TV which was then subsequently sold for $360 million. This generated attention and more business for the firm than Taxi is able (or wants) to handle.

“Turner Broadcasting invited us to do a pitch,” he said. “We were too busy so I referred them to Toronto and they won it. We have three or four full-time gigs and a lot of project work. Clients, which have agencies, want to use other agencies like us. They are not cheating but curious.”

Their New York clients also include Amp’d Mobile and Rail Europe. In July, Outdoor Life Network — a hockey broadcaster owned by Comcast and soon to be known as Versus — picked Taxi to handle its major re-branding campaign this fall.

Taxi is moving to larger premises to accommodate its growing staff, all of whom are in their twenties. Last month, Mr. LaVoie hired former Euro RSCG President, John Berg, to ‘operationalize’ the company as well as to relieve Mr. LaVoie from his role as acting President.

Taxi is now moving beyond its niche mandate into media planning for its clients only because the media is changing.

“In 1960, if you advertised on the three networks, you could reach 90% of housewives,” he said. “Today, you need 100 networks to do that. Now, the media is a dialogue. We’re conversing. It’s not talking at me anymore and the conversation is going on in all kinds of places.”

But the firm will remain focused. “We have no departments. We don’t do direct mail or media buying,” he said. “Big advertising agencies create beasts. They become pitch machines and pitch anything that moves. We’re small. We decline politely, not arrogantly.”

Mr. LaVoie said he chooses his clients just as they choose him — resulting in relationships not unlike successful marriages. “There are lots of bad marriages creating bad sex. We don’t want to do that.”