For what it's worth: I subscribe to several newsletters, some of which I always read, some of which I usually read eventually, some of which I really ought to unsubscribe from. Also (at leasr) one which seems to have fizzled out, and I was mildly irritated to see the author tweeting about how much he had enjoyed a gig which I would have gone to if he had sent out a newdletter containing that date.

Then again, calibrate for me as a person who treats my DW f-list as a sort of morning newsletter (so I was glad you made that link in your post), and Twitter as an instrument of the devil, into which I dip occasionally with a very long spoon.

And now, with my 'website manager' hat on: the marketing people will urge you to be ever-present on all the social media, but a more realistic aim is to find one that's a good fit for you, and stick with it. Maybe a newsletter that tells people when you've posted to a blog is the way to go, and then you have a platform where you can add in more infrequent events when / if they happen? But I do believe that readers can tell when something is forced, so if it doesn't feel natural, don't do it.