There are several important differences in the way imode and WAP based services are presently implemented, marketed and priced. Packet switching or circuit switching is a technical difference of the telecommunication system on which the services are based, it has nothing to do in principle with the imode and WAP standards itself. In principle, imode and WAP encoded webpages can be delivered over packet and circuit switched systems. There is not one single reason. It's to a large extent the fact, that NTT-DoCoMo made it easy for developers to develop imode websites, that PC's in Japanese homes are not so wide spread as in the USA and Europe, that local access charges are very expensive in Japan, so that Japanese people don't use PCs for internet access as much as in the US or Europe and several other reasons.
Japanese people love gadgets.
Relatively low PC penetration at home, high local loop access charges. Efficient micro-billing system via the mobile phone bill. Microbilling system makes it easy for subscribers to pay for value added, premium sites, and attractive for site owners to sell information to users. Fashion and efficient marketing. Uses cHTML, which makes it easy not only for developers but also for ordinary consumers to develop content.