As for the marketing, if someone reached out to me over twitter I'd rather not know that it was something they "built over the weekend". That might sound great for the HN crowd but as a consumer I'd like to know services are solid, stable, reliable and will still be here tomorrow.
I will say, though, there's a reason marketing is an entire function led by separate people. It's hard, uses different strengths and experience, and requires consistent effort -- not variations on "post it and they will come."
Where do you store your HN saved links though?
And those emails will either be conveniently ignored or will land in spam folders after a while.
If you don't have the time/discipline/motivation to read a article which is in your pant pocket, reminding you about it is hardly going to help your laziness/lack of motivation.
You might be right. But there's also the use case of it being just a timehop for your bookmarks vs. a read your unreads tool.