That was in Japan though.

By the time Digimon arrived, the Tamagotchi hype had already subsided a bit (at least here in Germany). And while I knew more girls with one than boys, there were several boys who did (including myself).

Both situations can be true at the same time. IIRC, Tamagotchi were a big hit where I live (Poland), I remember wanting to get one, playing with one someone had, and that it was discussed on a news program the other day - and popularity seemed gender-netural too. Everyone was fascinated with the new digital toy (well, kids were; parents not so much). Digimon came much later, past the popularity wave - and the only person I ever knew who had one (and still has it, and it still works) was my sister.

Apparently the Digimon device had a bunch of "social" features - multiple devices could talk to each other (don't remember if it was contact or infrared) - but I think she never met anyone else to test it with.