Depositphotos are clearly following in the tracks of big agencies like Shutterstock.
They push the high volume subscription plans as their mainstay. For the most part, you would have to say that it is working for them. They sell lots of images and are effective at gaining new contributors all the time.
Their royalty tier structure is a bit unreasonable, with the higher levels being near impossible. Each subscription download only counts as 1/3 of an actual download. Fotolia used to be similar, but got rid of this when bought out by Adobe Stock. Depositphotos should follow suit.
So you need a LOT of sales to reach the top. It seems to be only the big studios with teams of photographers or illustrators that reach the top levels. Or quality video producers, as video can't be purchased via subscription. So each video download counts as 1 download, not a third of one. The best bet is to start early and get those sales ticking over. Eventually you will gain a rank or two.
If you are an established stock contributor (a former exclusive at iStock for instance) then get in touch with them after opening your account. They may be willing to help you with getting your images online or maybe even pushing you up a rank or two.
All that said, the base royalty of 34% or 30 cents per subscription download is by no means the low end of the industry. So while you may not reach the top tiers any time soon, at least you are starting at a reasonable rate. This goes a long way toward us giving them a high score in our Depositphotos Contributor Review.