Tried it and hated it. Impossible to level up and the challenges were basically all won by high earning pro photogs. After a few months I threw in the towel.

Snapwire is a joke. They only favor the same people over and over again. If you look at their requests submissions, there are really good images which don't get nominated or bought, while snapshots from the 'pros' get nominated.
I wonder if their clients even see all the submissions.

I uploaded for a request recently to give it a try and got nominated. Let's see if it actually gets purchased.

Yeah, that's what I thought. Same thing on Imagebrief, never heard back anymore and gave up.