Hi
DT is good for exclusive contributors because you get higher commissions an visibility and get paid 20 cents per accepted image
Also DT has the best acceptance rate of all bigger sites.
they pay quickly but you have to reach 100 usd.
Anyway to get some money, and this is true for all sites, you need to upload some hundreds of pictures not few of them
To begin, I suggest to go exclusive in DT or FOTOLIA or Istock
depending on your picture quality and editorial content you have.
because DT accepts editorials, FOTOLIA not
Istock accepts editorials but it's very severe on them about description and caption.
and they consider editorials all the pictures that may have the minimal copyright issue, so you can get many rejections about this.
Istock doesn't show you the real earning up to the end of following month but its probably the one where you can gain more money.
Istock have the best acceptance rate for non-editorial pictures

and they pay higher commissions to exclusives contributors.