Fans of the photo sharing app Instagram will notice a change when they next check out their feed. The company, purchased by Facebook last year, is going to start showing ads to its 150 million users.

That move will present Instagram with a problem that’s become standard for social networks: Making money without alienating a hard earned user-base. “You’ve made people fall in love with you, but now you’ve changed the terms,” says Jen Drexler, Senior Vice President of Insight Strategy Group.

A survey from tech site Mashable found 43% of Instagram users are disappointed about the ads, 17% are furious. “There’s always a risk of alienating users,” says Dr. William Ward, a professor of social media at the S.I. Newhouse School of Public Communications at Syracuse University, “particularly if the ads are not well targeted.”

Still, Instagram ads could achieve the holy grail of marketing: Ads that people like and are willing to forward to each other, says Ken Wilbur a professor of marketing at the Rady School of Management at the University of California, San Diego. “The type of advertisement that I would expect Instagram to be selling are things like fashion ads, travel, high-end products. Things that traditionally have used high-quality images. Very often those ads are kind of fun and interesting to look at.” Much like the ads in a fashion magazine, which are often considered part of the content by readers.

In that case, Instagram should make sure the ads are Vogue quality, says Insight Strategy Group’s Jen Drexler. “If we’re looking at a liquor company that takes pictures of their cocktails each night, that picture had better be beautiful, it had better be something people want to share and not disruptive to the experience.”

Instagram has an edge with advertisers, since Instagram’s owner Facebook has loads of data on all of us: Our likes, our locations, and, of course, our cocktails of choice.