If any processor is based overseas, they arent required to collect the $750 visa fee from merchants. I know
ClearCard.com doesnt require it either, and they have been billing for sites for over 8 years, and they are integrated in nats and mpa3 as well.
I think it's possible that Zombaio can offer these rates, and don't be surprised if you see some of these other companies dropping their rates now too because they have been high for too damm long....