Dan Lewis started this newsletter about the same time I started my Hacker News related one so we have collaborated a good bit the past 2+ years. It has been awesome seeing how fast he has been able to grow it. He does a great job with the writing and finding things that you never have heard of... I can't recommend it enough!
I'm not sure to understand why.
In my case, I think that if if it happens that I receive the email in my phone (that is, when I'm not in frond of my computer), I'll make it as 'read', and it will be forgotten in the middle of the not-so-important emails (that is, outside of the inbox, in Gmail).
I only read rss news on my computer, so it's far more likely that I'll read and enjoy it!
Just a heads-up: when I signed up, the banner that shows on the "thanks for signing up" page links to "http://dlewis.net/nik/ which currently says "OK" and nothing else.
How do you manage to keep up with the content? I'm surprised at how you manage to dig up so many obscure and interesting tidbits of information so regulary.