This is also matter of perspective. If label has 1 CD, that is 300 copies, and he gets like 2-20 orders per year, it seems too slow. But if there is back catalogue of 20 releases, and you get 2-20 orders for each therefore even few hundred orders for items what theoretically can be labeled "doesn't sell shit" -category, I think it's pretty good. I think that is quite realistic, thinking at first you sell 10-100 copies and rest... will sit in storage and wait.
It's perspective one should remember. Many of the noise classics, MSNP tapes, DEADLINE tapes, GROSS tapes, PAIN JERK tapes... etc, they sold often mere 20-100 copies. Including distributors and waiting for paper flyers and catalogues to circulate.
Now people are in such an hurry, not understanding that if you make A GREAT and interesting release, it will take some time people can hear it. It just doesn't work only based on pre-order hype. There are other ways, but they may demand commitment for longer time.
We can now observe something like CONCRETE MASCARA album situation. Perennial Disappointment CD, 2016. Discogs lists 16 available, starting from 6 euro. Blossoms Of Shame CD 2014, one available, 10 euro. When this one is gone, my assumption is that it will be unavailable for a while. I don't think label made big deal that it was edition of 100. But it will soon be rather clear that it was perhaps even too small pressing.
A lot of releases I pressed on CD, are done 200 or 300. Very rarely I advertise size of pressing, be it small or big. A lot of CD's are very very low in stock now. A lot of them sold out long ago. Some have lasted nearly 10 years, but little by little, just about everything sells out. I think one thing what separates tapes and CD's, is the pace. Tapes were often treated as temporary. Tour releases, special releases, something short and quick - to make and to sell. For CD one may have to adjust into new state of mind, create things that you feel strong enough to stand for - possibly 10 years. And releases what you don't hate to see in bulk amounts in your storage boxes, hah...