If RO:Ost sold 400,000 copies (probably a bit more) and 14% still played the game after the achievements came out then those 14% are 56,000 people in absolute numbers. Still quite low?
The definition of Low or High is relative, so if we talk about a %, yes its still low. And that was the most basic of the achievements, the % is quite lower for the rest of them. Because 344.000 got the game and didn't kill 10 people (after achievements were added)
What I mean, is that in the end, only people who likes the game actually plays it... everybody has a lot of stuff to do in their lives, and if they don't, there are still infinite sources of entertainment.
So only people fit to play this game will do so, and will do it because they want it, regardless if they got interested in the game because they saw a hat in a TF2 announcement or because they saw a trailer... (I got interested in RO because I was looking for UT2k4 maps) the ways of the Lord are mysterious... :IS2: