Nearly anyone may list their wares on Amazon, but the ability to actually get your wares in front of customers is dependent on being able to ‘win the Buy Box,’ which is that white box on the right-side that you get to after you search for an item on Amazon.
Over 80% of Amazon purchases go through the Buy Box.
The Buy Box is the lever Amazon uses to control access to customers.
Amazon awards the Buy Box to merchants based on a number of factors.
One factor is whether a product is ‘Prime eligible,’ which is to say offered to Prime members with free shipping.
In order to become Prime eligible, a seller often must use Amazon’s warehousing and logistics service, Fulfillment by Amazon (FBA).
How do sellers handle these large fees from Amazon, and the inability to charge for shipping?
Simple. They raise their prices on consumers.
The resulting higher prices to consumers, paid to Amazon in fees by third party merchants, is why Amazon is able to offer ‘free shipping’ to Prime members.
Amazon uses its Buy Box algorithm to make sure that sellers can’t sell through a different store or even through their own site with a lower price and access Amazon customers, even if they would be able to sell it more cheaply.
冬瓜豆腐 means a lot more than simply "winter melon tofu" and that I would explain what its additional implications are.
CantoDict says it means "an emergency or crisis such as death" — that's putting it mildly.
Some native Cantonese speakers say that it means "die" — but that's putting it too bluntly.
The Baidu encyclopedia states that a winter melon is big and hard, while tofu is small and soft, but if either of them encounters an unforeseen misfortune and are thrown to the ground, they will be smashed to smithereens — sort of like Humpty Dumpty.
According to this explanation, dōngguā dòufu / dung1 gwaa1 dau6 fu6 冬瓜豆腐("winter melon tofu") implies that one has encountered an undesirable and unexpected consequence. I
In earlier times, it used to be common for people to use this expression euphemistically at funerals, but such is not the practice nowadays.