i think it is atari was more popular in europe as a whole and amiga was more popular in the us
The opposite is more true... The Amiga was a failure in US when it came to home market, but it did take of later in the video production/tv station scene in the US. The amiga was the biggest success in Europe and here in Norway i never saw a atari being sold in stores, but the amiga500 was sold everywhere and most people i knew had one themself.
Most americans i have talked to seem to know the Atari better than the Amiga, while the exact opposite is true here.