Originally Posted by
more4less
...with heavy loads and proof of it is that quite often there are op-ups. Very likely for this reason it is not eligible, as mentioned by airoli.
Actually, the logic here does not hold.
If indeed there are often op-ups on ZRH-GRU, then this means that there was an overbooked Y cabin and open seats in C and F. This is
precisely the situation in which an airline would want to leverage this bidding tool: Instead of giving out free op-ups, you now alleviate your overbooking situation by accepting "bids" from Y passengers to get them into C.
An airline will not offer the bidding tool if they are confident that they can sell out the front cabin at the regular C / F ticket prices.