Quake: the Offering hit position 25 in Gog's list of popular games. It is currently on sale as part of the Quake I, II and III bundle and by itself.
I'm not sure how popularity is calculated for the rankings, but I assume it's based on the recent sales numbers. I think it's pretty great if new people are still getting into Quake I, perhaps influenced by the recent mod releases :)
I took a screencap. There it is, in the bottom right corner.
http://imgur.com/Npr8eBy