I've gathered ca. 1000 emails so far on my new programming screencasts website. The call-to-action was "episode alerts", FYI.
For a while, I emailed out each episode, but I noticed that each email caused maybe 1% of the list to unsubscribe, which is painful considering how much effort goes into winning a subscriber.
I've since reduced the frequency of mails to every 3 or so episodes (i.e. every 3 weeks). But I can't tell whether this is good idea or not.
On the one hand, mailing every episode means my content gets more eyeballs (and more chance of some virality via social media shares). On the other hand, if I hold back on using the list, then I'll have a larger list to one-day pitch any eventual paid offerings I launch.
What would you do in this situation?
If you want to reduce them:
(1) make sure your content is important to the largest fraction of your audience
(1a) make sure each mailing contains at least something for all of your audience
(2) don't mail too frequently
(3) gracefully deal with unsubscribers, confirm that you have unsubscribed them on the page, do not send them more email
(4) really delete their email addresses, don't keep them around so you can mail them or sell them in the future
(5) make sure that your sign-up message matches the content of the thing that will be received
(6) of course, double opt-in every sign up to ensure that it is really the person subscribing and not some joe job.
(7) there will always be a fraction of your new subscribers that immediately unsubscribe after receiving the first email; this is called 'first contact churn' or some variation on that theme. This is perfectly normal and tends to be much higher than the churn from users longer in your system.
(8) Your list is as valuable as the engagement with your audience. People that do not engage with your content - whether you mail them or not - might as well not be in your system to begin with.