Tightrope is unrelated to premise. Please eliminate things which may obscure the message. The goal of memetics is to spread an idea, the substance is what's important. Use a base which better reflects the ideas you're trying to spread. You seem to be going for a theme of balance so in sticking with the theme I suggest the reference of "there's not enough room for the 2 of us" and integrate the idea of Amazon not playing fair into the analogy. Any depiction of cheating in sports or cards can convey the message. Suggestion 2 = Poker, post office has 3 cards, Amazon has 7 (took 2 of post office cards) implication that the game's not fair. Subtext importance matters as much as context. It's quite easy if you think about it.
Just a push in the right direction. You guys have some good memes but bad ones spoil the bunch (give the appearance of astroturfing)