Taking pictures used to be expensive.
First you had to decide what kind of film to use. Black and white, color negative, or color positive. A 24 shot roll would cost you $4-10, a 36 shot roll between $6 and $13.
Then you had to take the pictures. No clue how they eventually would look. But you took them.
Then you had to have the film processed and prints made. Developing would be $3-10, making prints anywhere from $6-20 depending on what you needed.
Taking pictures used to be anywhere from .30 to $1.55 per image, and most of the images were not worth keeping.
But the value was quantifiable because you paid for the process, and invested time.
And today? You can take a thousand pictures and not spend a dime.
So how do you add value when something costs nothing? If your customers are getting something for free, what is the true value of that thing? What did you bring to the equation to develop the value?
For photography, the value is in the quality and beauty of the image. And if you are the company that helps people make beautiful and free things, they will flock to you. Thank you, Instagram.
(Sidenote: read the book Instant: The Story of Polaroid and contemplate why Polaroid never became an Instagram. A fascinating thought.)