For the couple hundred images I have uploaded to their site, the sales for me are equivalent for mid-tier players like bigstock, canstock and veer. It mostly seems to be subscription downloads though, which is the disappointing part. But if you get a regular sale its a nice chunk of change.
Unlike Robert, I am not quite sold yet that their uploading is any easier, unless you have batches of the same thing. In comparison to a site like Canstock/123RF there are still way to many form fields you need to mess with to get an image through the process.