In 2012, Mark Zuckerberg's Facebook shrewdly signed a $1 billion deal to acquire the booming free photo sharing app Instagram.

Now, after doubling Instagram's user base to more than 200 million and quadrupling the number of shared photos to 20 billion, Zuckerberg is trying to recoup that investment.

About a year after launching in-stream Instagram advertisements in the U.S., and months after doing the same in the U.K. and Australia, the company began rolling out the first ads to Canadian users on Monday.

"Because we've always had big ideas for the future for Instagram part of making that happen is ensuring that Instagram becomes a sustainable business," says Facebook creative strategist Helen Pak, who helped co-ordinate the ad launch in Canada.

It kicks off with promoted posts from just six companies, Air Canada, Hudson's Bay, Mercedes-Benz, Sport Chek, Target and Travel Alberta.

Pak hopes Instagram users won't be startled by the ads and will barely notice them tucked between the stylized selfies and other photos and videos in their streams.

"We want to make sure that any ads you see in Instagram feel as natural to the Instagram experience as the photos and videos you already enjoy in your feed," Pak says, adding that she worked with advertisers to ensure their photos had the right feel to blend in.

"We are approving a lot of their creative, the ads are designed to be seamlessly integrated within the existing experience."

Not all Instagram users will see ads on Monday, according to Meg Sinclair, a Facebook communications manager.

"There's a chance if someone is a very light user of Instagram, like if they log in a couple of times a week and only follow a couple of different accounts and only spend a minute or two on it, that they wont see any ads at all," says Sinclair, adding that there's no established ratio of ads-to-regular-posts yet.

"I think it's too early for us to have that, I think we'll get a better sense of that eventually. For Facebook it took us a long time to really perfect — and I wouldn't say we've even perfected it — we're still tweaking and working on what's the best experience for people. But Instagram is still very early days."

While most users would rather not see ads if they don't have to, Sinclair notes many companies have built very successful Instagram profiles with thousands of fans who have voluntarily signed up to see promotional posts.

The Travel Alberta account has more than 92,000 followers and typically receives a few thousands likes per post, while Hudson's Bay and Air Canada have more than 24,000 followers apiece.

Pak says Instagram users have "absolute control" over their feed and can stop future posts from an ad campaign from appearing.

"If a person wants to hide a particular ad campaign that's being shown to them they're able to tap the three dots (icon) at the bottom right hand corner and hide that particular ad campaign, and also provide feedback," she says.

Keeping the user experience seamless is a key to introducing ads on social media, according to Abid Chaudhry, a senior analyst at BIA/Kelsey.

Users seem to be retaining information from ads because they check their account so frequently, he said.

"You always see a small segment of users that say they’re just not going to stick around for it," Chaudhry said in an interview with CBC's The Exchange with Amanda Lang

"But what Instagram has figured out and what a lot of social media services are figuring out is that native ability to show an ad in the screen itself and make it just as easy to see as another friend’s photo, which has made advertising actually become more effective."

He believes too few users will leave to have an impact on Instagram, because it has such a large base of fans.

With files from CBC News