This is just the North American sales of the first five days and not including the PSN version copies. In just 5 days it's sold about as much as the Japanese's lifetime sales.
NNK released a few days ago in EU and while there are no numbers yet it premiered in the UK at #1, the only non-Final Fantasy console JRPG to do that in the last decade. So it's doing well in Europe too
Looks like Level 5 may very well now do a Ni no Kuni 2 --- PSVita & 3DS
America is a much larger market and the Japanese market has different standards and expectations.. They distribute far more copies of the game in America so if they don't sell a whole lot then it won't be a big profit. 170,000 is not a lot by American standards.