Hi Sagar -
 
I'm sure team GCU will tune in and clarify further, but I'll share what I know.
 
The 'incentive' you refer to from bulk sales is not correct. You are speaking of the threshold earnings and that has nothing to do with bulk sales, in fact artists would get those premium earnings quicker with more single sales vs bulk sales because the artist earns more on a single sale, generally speaking.
 
So, EVERY artist and EVERY sale an artist makes gets them closer to any quarter's given premium earnings.
 
No other 'incentives' exist - I've sold nearly 560,000 cards since I started GCU and trust me, the premium earnings is incentive enough. All artists should push to reach that threshold EACH QUARTER as it nearly doubles your earnings.