Since email newsletters are one of the services we offer, inevitably, people ask us about best practices for building their email list.
Unfortunately, sometimes people get confused about “best practices” and “how do I get my newsletter numbers up super-high, because everybody knows bigger lists are better, right?”

Right?
Allow me to share a personal story.
I checked my personal email a few weeks ago and noticed a message from a name that seemed vaguely familiar, but wasn’t one I recognized immediately. Turns out it was a newsletter advertising a new book being released by an author I’d never heard of.
Confused, I scanned the newsletter and realized it was sent from Mailchimp, which is the service we use and encourage our clients to use. Because of this, I knew there had to be a list description SOMEWHERE in the email that would tell me why I was getting this newsletter. (Maybe I had signed up for this and just forgotten about it. It’s happened before.)
(What’s a “list description?” Reputable email newsletter services usually require a list description before you can start sending out emails.
They usually look like this: “You signed up for the free coupon on our website” or “You checked the ‘newsletter’ box on the comment card at our restaurant” or “You signed up for email at the lunch seminar.” This lets people know you are not a dirty spammer. Anyway. Back to our regularly scheduled post.)
Sure enough, I found the description: “You are receiving this email because someone believes you should read this novel.”

O.o
Just in case you’re wondering, that’s not a list description. That is a one-way ticket to me reporting you to Mailchimp for spamming.
I am sure the sender didn’t think they were doing anything wrong. (I am a firm believer in Hanlon’s Razor: Do not attribute to malice that which can be explained by stupidity.) But that doesn’t change the fact that I didn’t sign up for that newsletter and I didn’t want that newsletter. It annoyed me.
Just for the record: annoyed people do not buy from you.
This is a case of Unwitting Newsletter Douchebaggery, a phenomenon Sarah over at Smart Bitches goes into with great detail. (She also talks about how to report newsletter abuse to the various email service providers.)
Author Courtney Milan published a companion post the same day, talking about the error of numerosity. Her advice doesn’t just apply to authors, but to anybody who uses a newsletter as a marketing tool.
Don’t add people to your list willy-nilly. Don’t be one of those companies that auto-checks an “add me to your newsletter” button on every single contact form.
Don’t put someone on your list just because you got their business card, or because you emailed them once, or because they sent you a condolence letter when your cat died.
Your email list numbers might go up, but the important metrics—your opens and clickthrough rates—will not.
Bigger lists don’t always equal bigger sales. Sometimes they just equal bigger headaches or bigger spam reports.
And that’s no fun for anyone.