Earlier quoted context omitted.
Part of the problem is that so many of the 'actions' people take with email are invisible to the sender: If the recipient marks you as spam, filters you to junk, blocks you as a sender or their client/provider auto-files you away somewhere, you as the sender get no indication of that. People won't click links in emails they've never opened, let alone read. 'Verification' tends to decay over time - even if I clicked t…
What I do with the email is invisible to the sender and it's ok. It's actually the way it should be. I clearly expressed interest in your newsletter by confirming the double opt-in. It's also ok if I open your newsletter only once in a while, I may be busy, or I only want to read your content when its title click something in me. The most successful newsletters respect this and did so for so many years. They never me…
Newer newsletters don't have that reputation, so they are more heavily penalized for low open rate or higher spam flag rate. Thus, they need to react more quickly to users invisible actions or risk damaging their reputation. I don't think this is a growth hack, I think this is a necessary action as a new entrant in a very unforgiving space - see some stories upthread from legitimate newsletters.
While your actions are invisible to the sender, they are _not_ invisible to your email provider, and ultimately they are the ones who make reputation decisions that can destroy a newsletter.