Crestock made some changes on their site, they now have subscriptions. I stopped uploading there a while ago, lets see if this brings more sales.

"For credit sales the contributor gets 20% of the sale sum. For sales of small size images, this equals $1 per download, for medium sizes $2 and for extra large sizes $3.
For subscription downloads, there is a flat rate of $0.25 commission per download.
After 100 downloads you get 30% commission on credit downloads."