Sales dropping over time is more common [1] than unexpected $10k charges to a credit card. It also has many more explanations. The scenarios are so different, the analogy is frankly dishonest.

[1] It is, in fact, the rule. And can be much faster and bigger than 40% in 3 months: https://www.addthis.com/blog/2014/04/21/can-social-buzz-pred...