Being successful on Instagram is simple — but it's not easy. Louise Delage nailed the not-so-secret Insta formula of being a beautiful young woman who showed some skin and traveled the world in glamorous (yet obtainable) style.

The young Frenchwoman's account went live on Aug. 1, and within a few months, she had racked up 50,000 followers. There was evidence of all the things an Instagram account needs: Exotic locations, great-looking friends, delicious meals, and no sign of the stresses of life.

But there's a secret to Louise's account — and it's not in how quickly she racked up tens of thousands of followers.

t's not in her hashtags, which are the usual: #instatravel, #trip, #travelgram #instago #flashesofdelight #mytinyatlas, etc. Nor is she using any special filters....

Can you tell what's really going on here yet?

"Louise Delage" is actually a French student, and her secret isn't just that she's posing as a faux persona; it's that she's doing it for a reason: It's part of a campaign for Addict Aide — a French group that helps alcoholics sober up. The campaign was made by an ad agency in Paris, and from the comments and likes, nobody seemed to have noticed that in every picture, there's alcohol, or a reference to it in comments by "Louise."

While in some cases, the drink is hidden a bit (check the glass in the background, below), it's always there. Sometimes, it's almost out of the frame, or there's a bottle in a bag, or the beverage is in a shadow, but a beer, wine or mixed drink is omnipresent.

Once you know the secret, it's completely obvious. And you might be easily tipped off if you look at all her pictures in a row; but if you're like most Instagram users, and simply shuffling through your feed and you see Louise Delange's pix mixed in with all the others you follow, you probably wouldn't notice.

And that's the point that the ad agency is trying to raise; "She's the girl next door, she could be your daughter or someone you know," the ad agency exec behind the campaign, Stephanie Xiberras, told CNN. "You can miss something like this."

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.

This Instagram star's message will surprise you
Can you figure out what she's really selling?