DT sales are so tiny (for me) that it hardly matters...
However, I started using StockSubmitter (and am now using the beta version of the web version of it) last October. I now just enter once, and SS takes care of all the agencies, including DT. Thus, DT now quite literally takes me zero time to submit, so I went ahead and did it.
By adding roughly 1000 new images to DT, I now get as many as one new sale per week! (yes, I make about $1/mo with those extra 1000 images -- like I said, so tiny it barely matters...)