Originally Posted by LUGlodo

Can't speak to your exact case, but in both my last two GRU-ZRH and ZRH-GRU flights I received the upgrade email. Price range was ranging from CHF 860 ("weak chance") to CHF 3'250 ("excellent chance") (who would bid that?).

I did not participate in the bid, but in one of the two occasions I received an email two days before departure with an offer to upgrade for CHF 999. I accepted it after making sure that this would book into D class and give enough miles to reach Senator this year

Given that short-term fixed-price upgrade offer I wonder how many people actually bid the upgrade to business at anything above what Swiss considers "weak"