You are exchanging gold both for items, and for services (players participating in the kills). Because of that it is not just a loot system, it is a paid service and loot selling system. That is because the gold is involved.
Blizzard recently defined what they view GDKP as when they restricted it in SoD. I know you are not playing in SoD, but knowing how Blizzard defines GDKP helps you realize why it falls under Services, not group finder. These two quotes should help make that clear.
What is GDKP and why is it being restricted in Season of Discovery?
GDKP is a loot system some players use that essentially allows all loot to be purchased in a dungeon or raid using gold rather than being rolled for or awarded using another loot system. How this typically works is that an item drops and is then put up for gold bid among the members of the group. Players will submit their bids in gold, and the highest bidder wins. After the item is won, gold is traded to the loot master, and then that gold is usually divided among all the raid members.
What exactly constitutes a “gold bid” or GDKP raid?
- We’re defining GDKP as any raid or dungeon run where items are awarded in exchange for gold. Please note that we have multiple detection methods for GDKP that are effective both inside and outside of dungeon or raid instances.
Now that you know Blizzard defines it as a Service like a carry, because gold changes hands, you know to follow the guidelines from the Advertising article. In the absence of Trade Services, use Trade.
Sendryn’s suggestions are excellent to assist you in avoiding getting reported for spam, or other infractions. Why are mass reports still abusable? - #26 by Sendryn-sentinels