Geralt_of_Rivia: They usually don't.
onarliog: What is that "Next in" counter on the front page for? Have they been revealing new bundles everyday like before? Since there were so many of them to begin with this time I didn't really pay attention, and assumed they did it Steam style with everything put on sale on day 1.
I'm also not sure if there were new bundles but there were definitely new games offered every day when the counter hits zero.
kbnrylaec: During this winter sale:
We are the Dwarves: 67% off -> 75% off -> 67% off(now)
<span class="bold">Civilization Bundle</span>: its counter clock is much much shorter than other bundles.
Last (I-forgot-its-name) big sale:
Torchlight II: 85% off -> 67% off -> 0% off
Usually they do not change discount in a big sale, but...well, it happens all the time.
Sometimes the offer is correct but the percentage is shown wrong. GOG's website isn't 100% bug free.
Sometimes (like in the Torchlight II case) GOG makes a mistake. They did offer the game 85% off but it was supposed to be 67% off. Since GOG has to sign off such deals with the publisher/developer they can't make a better offer than what was agreed on so they corrected their mistake as soon as they realized it. And when too many people complained that they made the offer worse they took it out of the sale completely. That's why we can't have nice things.