I didn't know about that puzzler. So, in some ocassions there are contests where chess.com give diamond memberships? Do you know about others in the past?
https://www.chess.com/forum/view/community/reward-earn-diamond-membership-by-finding-and-reporting-bad-ads
you're late.
https://www.chess.com/article/view/can-you-solve-our-2018-holiday-chess-puzzler
I didn't know about that puzzler. So, in some ocassions there are contests where chess.com give diamond memberships? Do you know about others in the past?