There’s no such thing as a free lunch. And soon there won’t be such a thing as a free photo-sharing app. The “price” users pay for no-cost apps and content is having to look at the advertisements that support them. But until now, Instagram’s 150 million users have been free from such annoyances. The remarkably popular photo-sharing app, now owned by Facebook, has never sold ads. But with Facebook, now a public company and seeking to monetize all the eyeballs across its platforms, Instagram is looking into selling advertisements.