I have been Pming people in a fitness site if i could use their before and after pics in my site. Unfortunately, none wanted any part of it. Some were mildly interested, but they wanted more than the usual exposure and backlink that i would offer to their site.
It is frustrating to know that i have been in that site for some time now, and i really didnt expect that much rejections
Most of their replise had "what's in it for me" or other forms of the same meaning.