The genie is already out of the bottle. People have already lost their trust with Instagram, I did at any rate. Problem is if you try high handed strategy like they did, as in we will sell your pictures without giving you a single dime, people will react. And they did. What they should do was to follow deviantart's model. Grab a percentage from the sold, printed out photos. Or put in a premium package. Or both.

This is my two cents anyway.