I think it's true that Nokia did not sell too many n900's (just a quick question to english people: is it correct to write "n900's" or "n900s" to make the plural?).
Many people I know they even don't know what n900 is. They had never seen it before. In the region where I live (Italy) I could never see the n900 in hypermarkets or superstores (where the majority of people by phones). All the other phones (Nokia and others) are there, except the n900. The n900 is existing just in the Nokia shops.