Originally Posted by
IMOA
That's certainly not the case, in fact I've always flown into the US on a business ticket and always flown the domestic segment in what is comically referred to as first class.
I think that what ralfp meant was that--while business class transfers to 1st class in US domestic--if you change airlines, you tend to get the lesser of the two. If you're flying the same airline or a partner of the original airline, it's different.