Instagram is about to add more ads to your feed

Instagram users love scrolling through their clean, unfettered, (mostly) ad-free streams of photos. But the company is about to bulk up on advertising, putting more sponsored content into feeds.

In a post on its Instagram for Business blog, the company said that it is expanding its year-and-a-half-old advertising program. It's unclear what exactly that will mean, but one thing is for sure: Whatever form ads take, there will be more of them.

CBS News contributor and NewYorker.com editor Nicholas Thompson said the change was "inevitable." Instagram started sponsored brand content in late 2013, but a noticeable increase in advertiser presence is imminent. "It's surprising they haven't changed until now," he told CBS News.

"Instagram is a lot purer (than Facebook) for a lot of different reasons. You can't even click out of it, there are no links in it, you can't go anywhere else -- you just stay in the feed. It's very seamless, it's very pure, it's very relaxing for a lot of people. But it also means that nobody makes any money off of it. Publishers don't get links to their stories, advertisers don't get anything. Instagram doesn't get anything."

Instagram's post said it is "expanding ad offerings to include action-oriented formats," which means new experiences for users, including "shop now," "install now" and "sign up" buttons.

There will also be "more targeting capabilities," to drive paid content to certain users and Instagram said it will make it "easier for businesses large and small to buy ads on Instagram." Translation: More ads, more ads and more ads.

Instagram said it will start testing action buttons in the coming days; the full roll out probably will come at some point this year.

The company will be leveraging the ad infrastructure of its parent, Facebook, which is under pressure from investors to bring in revenue from Instagram, acquired in 2012 for $1 billion. There are more than two million active advertisers on Facebook.

It's up to Instagram to grow advertising in a way that doesn't turn off users. But if things don't go well, it's Facebook, Thompson said, that will feel the burn.

"If Instagram gets cluttered, people...are going to blame it on Facebook. They're going to say, 'This big evil, stinky corporation ruined this thing I used to love and now I'm going to Snapchat.'" With young users increasingly moving away from Facebook, that is exactly the opposite of what it hopes to gain (besides lots and lots of money).